The Bount Invasion was a major conflict detailing the war between the Soul Society and the last remnants of the Bount. It was an invasion held by Jin Kariya and his followers Gō Koga, Yoshino Sōma, Maki Ichinose, Mabashi, and Sawatari.
The conflict started when Ichigo Kurosaki and his friends returned from the Soul Society after rescuing Rukia Kuchiki and they are put through various tests by a group of Modified Souls created by Kisuke Urahara for the purpose of training them.
The conflict ended when Ichigo defeated Kariya, the leader of the Bount and returned to Karakura Town with his friends once again.
After arriving back from Soul Society, Ichigo has difficulty readjusting to everyday life, but is thrown back into things when Orihime Inoue is kidnapped. Ichigo and friends are then put through a series of tests with more and more people eventually disappearing after each test. When finally Ichigo's group confront the three kidnappers, they learn the entire thing was a test orchestrated by Urahara and everyone is informed of the Bount.
Urahara explains that the three kidnappers are Modified Souls that also serve as Bount sensors and gives a different one to Ichigo, Yasutora Sado, and Orihime. All three sensors detect a Bount later and Ichigo is the first to arrive. Ichigo battles against the Bount, but struggles greatly until Rukia arrives. Another Bount arrives and kidnaps the first, ending the battle. Later, Ririn senses another Bount and everyone heads off to find him. They engage Utagawa and he begins fighting dirty, trying to attack the powerless Uryū Ishida. Before Utagawa can get his hands on Uryū though, Yoshino arrives and saves him, taking the Quincy with her. Utagawa is then forced away by the arrival of Tessai Tsukabishi, Lieutenant Renji Abarai, Jinta Hanakari and Ururu Tsumugiya.
Uryū is later found in Karakura Hospital and when his friends arrive, he tells them what he learned of the Bount, namely that they are beginning to consume Human souls and that a Quincy is needed in their plan. The sink then starts flooding and they try to stop it, but have no success. The water then begins to attack the group and a struggle begins. Everyone finds it difficult to battle water as it constantly reforms itself as it goes after Uryū. The battle continues, but the group still has no luck in destroying the water. They eventually get out of the hospital and confront the two young Bount. After separating the two, Ganju Shiba arrives and with the aid of his fireworks, defeats the two Bount, earning the team their first victory against the Bount. However, Uryū has gone missing. After collapsing in the street, Uryū is saved once more by Yoshino. She takes him back to her room and explains more of the history of the Bount. However, their time is cut short by the arrival of Gō Koga, who manages to capture Uryū and Yoshino. They are taken back to the Bount's mansion and Yoshino is thrown into a cell. Kariya confronts Uryū then and asks him to join the Bount. Uryū refuses and he is locked in a cell. Meanwhile, after searching for some time, Ichigo and the others arrive at the mansion and after some difficulty getting in, they manage to finally enter the mansion where they are greeted by the Bount.
In the Bount mansion, Ichigo and his friends are confronted by Jin Kariya, who greets them and calls Ichigo by his full name. Shocked, Ichigo asks how he knows this and Kariya says that it is his business to know. Ichigo says he is going to take Uryū back, but Kariya says he will not give him up. Ichigo prepares to fight the Bount when Ryō Utagawa activates his doll and attacks. Ichigo worries about taking seven Bount on at once, but Utagawa says that Ichigo will only fight him. Utagawa asks Kariya to remove his crest and he does so, placing it on the ground. Utagawa begins sending snakes to attack Ichigo who struggles at first. Ichigo tries to cut Utagawa, but Utagawa merely uses his snakes as a shield. Finally, Ichigo manages to cut his opponent, but a Pentagram appears under Utagawa and a mass of snakes attacks Ichigo from all directions. When Ichigo is finally able to destroy them all, Utagawa has his snake steal Kariya's crest. He explains that with that, he will become the leader of the Bount. However, Maki Ichinose appears and kills the traitorous Bount and then prepares to battle Ichigo.
Ichigo and Ichinose begin trading blows, but Ichinose gains the upper hand with his speed. Ichinose then uses a special attack from his Zanpakutō to envelop Ichigo in light. Ichigo is then attacked by shadows. Slamming his Zanpakutō into the ground, Ichigo is able to save himself with a small explosion. Kariya then steps in and says that he will finish things as he has taken an interest in Ichigo. Kariya asks Ichigo to join them, but Ichigo quickly declines. Ichigo attacks Kariya, but it is useless. Kariya places a finger on Ichigo's head, immobilizing him and then flicks him, sending him flying against the wall. Kariya and Ichinose begin to walk away then, but Ichigo gets up, prepared to continue. However, the mansion is attacked by Ururu and Jinta. The Mod-Souls find Uryū, who then runs to get Yoshino. Everyone flees the mansion then. Later that night, the Bount examine the ruins of the mansion and Kariya tells the others to let things be.
Later, at the Urahara Shop, Yoshino and Uryū talk about Kariya. She says that she does not really understand what he is trying to do. Uryū asks her about her pride as a Bount and she relates it to his Quincy pride. She says that the Bount are unable to reproduce and that they will fall to ruin over the years. As Uryū falls asleep, she gets up and gives him a kiss on the forehead, thanking him and saying goodbye. She then leaves the store and heads to the Bount mansion. She confronts Kariya, who tries to reason with her one last time, but she summons her doll, asking if it would not mind dying here with her. He understands and attacks Kariya, but Kariya is too quick. Yoshino is nearly hit by one of Goethe's fire blasts and Kariya warns her of her power. He then reveals that Yoshino is the only Bount with the power of motherhood. He grabs Yoshino and tells her he needs her power. Crushing her crest, Goethe goes wild and burns Kariya's shirt off, revealing that he has a crest on his chest and that he has merged with his doll. Yoshino then call Goethe, who attacks Kariya only to be killed. However, the pieces of him enter Yoshino and they fuse. She makes one final charge at Kariya, who strikes her down. Her body then disappears into a green light which forms at Kariya's feet. He recites a chant and a red seal appears. Dozens of eggs emerge from the seal and hatch, becoming the Bitto. Kariya and the Bitto then disappear.
Inside a cave, Kariya explains the new Bitto to the other Bount. He tells them that the Bitto collect the souls of living humans and that it is highly purified. He calls a Bitto over and pours its contents into a glass. Drinking from it, his power increases wildly. All the other Bount agree to take part in drinking from the Bitto with the exception of Mabashi, who refuses. Kariya punishes Mabashi for this and then states that he is the new law. The Bount then drink from the Bitto, gaining a large increase in power and Kariya goes over to Mabashi and forces him to drink. Meanwhile, in Soul Society, Captain Tōshirō Hitsugaya has formed a team of Lieutenant Shūhei Hisagi, Yumichika Ayasegawa, Lieutenant Rangiku Matsumoto, and Lieutenant Izuru Kira to investigate the Bount in the Human World. In the Human World, the Bitto have swarmed the streets, taking many souls. Keigo Asano is attacked and left unconscious. When Ichigo arrives and tries to take him away, Gō Koga arrives.
Ichigo is quickly overwhelmed by Koga's doll, Dalk, who fires off metal balls at him. Ichigo tries to fend them off, but has little success. Dalk finally manages to capture Ichigo and takes his Zanpakutō. She is about to finish him with his own sword when Ichigo's inner Hollow takes over and grabs the sword back, throwing Dalk in the process. He then takes control of the battle, easily overwhelming Dalk, but soon his hand is forced on his mask. Ichigo manages to break through and remove the mask, but collapses. Dalk goes to finish Ichigo, but is stopped by the arrival of Kira. Kira battles the doll and through the special ability of his Zanpakutō, manages to defeat it. Kira and Ichigo then head to the Urahara Shop with Keigo. Meanwhile, Rukia and Orihime are confronted by the Bount Yoshi. Rukia tries to fire off a Kidō spell at Yoshi, but she dodges. As she tries again, she notes that without the incantation, her spells will not work against Yoshi. Kurōdo then changes into Renji's form and attacks. Orihime tells Rukia to start the incantation and helps Kurōdo with her Koten Zanshun. Rukia fires off an incantation enhanced Hadō #33. However, Yoshi manages to knock Kurōdo back to his original form. The group then tries to flee and Yoshi fires needle-like projectiles at them, but these are stopped by the arrival of Mabashi. Mabashi summons his doll, Ritz, and has it attacks the group. Rukia tries to fend it off, but it is much too fast for her. Ritz then hits Rukia and enters her body, knocking her to the ground. Mabashi then tells her to get up and introduce herself and she complies, revealing that Mabashi can control her now. Rukia attacks Orihime, but Orihime manages to use her shield. Orihime pleads with Rukia, but Mabashi says it is no use. He then orders Ritz to draw more power from Rukia and she does so, changing Rukia into her Shinigami form. Orihime struggles against her friend, but will not harm her nor Mabashi. Mabashi then orders Rukia to finish Orihime and she swings her sword down at Orihime, but it is blocked by Shūhei Hisagi, who arrives on scene. As Rukia continues to attack, she regains a part of her self and tells Orihime that she needs to kill her. Hisagi says that this is the greatest sympathy Orihime can give her friend. Orihime finally resolves to do it, but walks up to Rukia and hugs her, using Santen Kesshun around the two of them. Ritz cries out in pain and leaves Rukia's body. Hisagi then goes to finish Mabashi, but Ichinose appears and takes him away.
Later, in Karakura Town Park, Sado, Ururu, and Noba are confronted by Sawatari. Rangiku arrives and Sawatari brings out his doll, Baura. The Bount disappears into the ground, confusing the group, but Noba is able to warn them just in time as he reappears. Sawatari explains that his doll can manipulate space and time like Noba except that Noba is weaker. Rangiku then releases her Zanpakutō to attack, but Baura begins sucking up the ash, forcing her to seal it again. Rangiku calls Soul Society and has them protect the area so they do not have to hold back any longer. Sado brings out his armored arm and attacks, but the doll escapes. As the doll comes back up, Ururu pushes Sado out of the way and is eaten by the doll. The group then makes a plan and tries to rescue Ururu, but Noba gets injured during it. After a few more failed attempts, the group runs and forms a new plan. Rangiku tries to locate Sawatari, but Sawatari appears right above them. Sado then punches Baura in the stomach and the doll begins throwing up everything it has consumed, including Ururu. Sawatari then retreats. 
After the fight with Sawatari, everyone regroups and is given time to heal. Soon though, they head out and find the cavern where the Bount have been residing. They enter the cave, but are soon confronted by Ugaki's doll, Gesell. Numerous floating eyes and hand attack the task force and Yumichika is swiftly defeated. The arrival of Ichigo and his friends does not make things easier when Gesell overwhelms them as well. Ichigo and his friends are soon caught in ropes, but are freed by Rangiku's Shikai. She informs them of Ugaki's power and warns them to destroy everything that casts a shadow. Everyone splits up then and Ichigo and Renji go to find Ugaki. As they search, they are swarmed by more eye creatures and falling spikes. Ugaki then releases Gesell's ultimate form and a monstrous purple figure appears. Renji releases his Bankai to do battle with the creature and is able to counter the creature's axe like arms with the extendable parts of his Bankai. Ugaki then realizes that Uryū had made contact with Lieutenant Nemu Kurotsuchi, who has given him the Quincy Bangle. Ugaki relays this to Kariya. Renji then slams the parts of his Bankai into Gesell, causing the creature to writhe in pain and reveal Ugaki's location. Ugaki asks for help from Kariya, but Kariya simply bids Ugaki farewell as he is crushed by his own doll. Ichigo then hurries ahead and enters a room with all the other Bount.
Kariya confronts Ichigo and Ichigo is soon able to realize that Kariya killed Ugaki on purpose. Kariya then decides he will test his new power on Ichigo. Ichigo rushes forth and swings at the Bount, but Kariya stops the blow with ease. Kariya knocks Ichigo to the ground and then picks him up by his hair before punting him away. He then explains his plan to enter Soul Society to get revenge for the Bount ever being created. He explains the history of the Bount to Ichigo and says that he will annihilate the Soul Society. Kariya continues to pound Ichigo then before picking up the Shinigami's Zanpakutō. As he prepares to kill Ichigo with his own sword, Ichigo thrusts the sword into his chest. Entering his inner world, Ichigo talks with Zangetsu before returning to the cave and holding Zangetsu for himself, not Kariya. He then activates his Bankai and fights Kariya on even terms. As the two clash, however, an arrow is shot between them and into the gate the Bount had been preparing. Uryū appears with the Quincy bangle activated and lets the Bount head to Soul Society. He explains that while the Bount may get stronger there, so do Quincy and Shinigami. As the rest of the group arrives, they decide to head to Soul Society. 
As the Bount arrive in Soul Society, they are confronted by the Second and Seventh Divisions. Lieutenants Marechiyo Ōmaeda and Tetsuzaemon Iba lead their divisions against the invaders. They do their best, but are easily dispatched by Koga's doll, Dalk. Meanwhile, Ichigo and friends arrive in Soul Society and seek out Kūkaku Shiba's home. Once there, Yoruichi Shihōin tells them they need to get data on Ran'Tao, who was the leader of the research team that created the Bount. As the rest of the group leaves, Kūkaku asks to speak to Yoruichi privately. Kūkaku says that Yoruichi is hiding something and wants to know what. Yoruichi reveals that she is not going to Seireitei because of Ichinose. She says that Ichinose's abilities have allowed him to manipulate the data on the Bount and steer Captain Mayuri Kurotsuchi to giving Uryū the Quincy bangle. She does not want Ichinose figuring out their plan and has chosen to stay at the Shiba residence. Kūkaku then asks if they can win, but Yoruichi is unsure. As Rukia walks through Rukongai, she is confronted by Yoshi, who immediately summons her doll. The Bount taunts Rukia about her fight against Mabashi before Rukia grabs a katana from the nearby wall. The two attack each other, but Rukia is overpowered. Yoshi taunts Rukia, but Rukia says not to underestimate her. Just then, Ririn creates an illusion to distract Yoshi and tells Rukia to attack. Rukia fires off a Kidō spell. Yoshi is badly injured, but recovers by absorbing spirit particles. As the two continue to fight, Yoshi begins to take the upper hand again and Rukia is forced to run. As she runs, she comes across a child. Rukia tries to protect the child, but Yoshi threatens the kid. Yoshi kicks Rukia into the air and prepares to finish her, but is stopped by the sudden arrival of Captain Byakuya Kuchiki. Yoshi then escapes. 
Later, as Byakuya walks through the forest at night, he is confronted by Kariya. The two attack each other and Byakuya is surprised at Kariya's ability to use Shunpo. Kariya notes Byakuya skill and says that he is glad that he got a chance to test his skills against him, saying that Byakuya is known to be the greatest leader in the history of the Kuchiki Clan. Byakuya attacks with Senbonzakura and Kariya narrowly escapes and notes how Senbonzakura is truly beautiful. Kariya attacks with his wind and Byakuya counters with Kidō. As the fight continues, Ichigo notices the battle and fires off a Getsuga Tenshō at the area. Kariya then heals himself as Byakuya and Ichigo both activate their Bankai. Ichigo attacks Kariya, but Byakuya attacks both of them. As the battle continues, they are interrupted by something crashing into the battlefield. A woman walks out of the crater and reveals herself to be Ran'Tao. She confronts Kariya and asks if he is going to kill her, but Ichigo jumps in front to protect her. Byakuya then attacks Kariya, but is interrupted once more by Koga arriving. With the distraction, Kariya and Koga manage to get away.
When a group of Shinigami begin to head towards the location of the Bount and the mercenaries from Kusajishi that they got to join their side, Ichinose requests to stay behind to fight. Kariya allows it and Ichinose is then confronted by Hitsugaya. Soon, Ichigo and his friends arrive and witness Ichinose engaged in battle with Hitsugaya. Ichinose then releases his Zanpakutō, creating illusions and pitting Hitsugaya up against Renji. The illusion is soon broken by the appearance of Captain Kenpachi Zaraki. Kenpachi says he will fight Ichinose himself and the two clash. Ichinose questions how Kenpachi became a captain with his attitude. As the two clash, Kenpachi claims that he just fights for fun. Ichinose then gets serious and says he will use the true power of his Zanpakutō. A light envelops Kenpachi, who is then forced to take off his eye-patch in order to nullify the attack. He strikes back, wounding Ichinose and tries to leave then. Ichinose will not let him and the two gather all their strength in one last clash. Ichinose then falls to the ground as Kenpachi walks away. In Seireitei, Captain Suì-Fēng is informed that several members of her division have taken on a Bount and they have lost contact with them. As she prepares to leave, a member of the division throws something at her. She falls down in pain and realizes she has been poisoned by one of the Bounts. She heads off to take care of her wounds when she is confronted by Mabashi. He informs her that the poison is incurable and that she will die soon. The two clash and neither gains an edge. As she realizes she is very weak, she tries to end things quickly by releasing her Zanpakutō, but the poison prevents her from doing anything. Mabashi flees, but Suì-Fēng catches up and lands a hit on him, leaving a crest. A group of division members show up to apparently take Suì-Fēng to be healed, but when Mabashi calls out his doll's name, they all turn on her. She then activates Shunkō to get rid of her attackers and stabs Mabashi, revealing she already cured the poison with an anti-venom. Mabashi then falls to the ground and is attacked by his own doll before dying.
Elsewhere, as Sawatari heads through Seireitei, he is tracked by Mayuri. When Mayuri reveals himself, the two engage each other. Mayuri states he knows of Baura's ability thanks to Rangiku's data, but is then shocked when Baura enters his dimension through the air. The doll manages to take out Mayuri's left arm and Mayuri is forced to regenerate it. Mayuri pulls out his kusarigama and attacks, but Baura blocks. Mayuri leads Sawatari and his doll into an open area and detonates some explosives, filling the area with smoke. Mayuri jumps up and stabs Sawatari in the arm with his Zanpakutō, paralyzing it and leaving Sawatari unable to heal it. Baura and Sawatari enter the other dimension and try to escape, but when they come back up, Mayuri is already there and reveals his Bount tracker. Sawatari then gets serious and Baura begins firing off absorbed Kidō. Mayuri loses the left side of his body in the attack. Frustrated, he calls out his Bankai to end the battle and the poison kills Sawatari. In another part of Seireitei, Uryū takes on Yoshi. After dodging her initial attacks, Uryū takes the battle elsewhere. As the two fight, Uryū has trouble controlling the Quincy Bangle. Yoshi takes this to her advantage and uses her offensive form to cause Uryū to stay on the run. Finally, Uryū manages to fire a fully powered arrow straight at Yoshi, but is shocked when she reveals her defensive form and is unharmed. Yoshi then goes after Uryū and strikes his shoulder, badly wounding him and sending him flying. Yoshi chases after him and is about to spare him and leave when Uryū fires an arrow at her back. The two re-engage, but after they clash for a little, Uryū manages to end the fight with a point blank arrow. Yoshi dies and he heads off, badly wounded. Meanwhile, Kariya and Koga walk through Seireitei, but Kariya betrays Koga, attacking him and leaving him mortally injured. Kariya then goes and breaks into the Shinigami Research and Development Institute and after a confrontation with Ichigo, obtains the Jōkaishō. Kariya then watches the sun rise on a rooftop, but finds himself confronted by Ran'Tao who fires off concentrates spirit blasts from a gun she is holding. Kariya says that will not be enough to defeat him and Ran'Tao notices the crest on Kariya's shoulder and is shocked. Ran'Tao then explains more of the history of the Bount, saying she tried to defend them, but Central 46 decided to exterminate all of them. She traveled to the Human World to try and save them, but the Shinigami has already began killing all the Bount. She reveals that she saved Kariya and gave him his crest, but afterwards was captured by the Shinigami. 
After recovering from Kariya's betrayal, Koga is confronted by Hitsugaya. Koga summons Dalk and the doll surrounds Hitsugaya, but is cracked open by the release of the captain's Shikai. The battle continues on a roof and though Dalk manages to keep Hitsugaya on edge, Hitsugaya encases Dalk in ice and sends her off the roof, shattering her into a million pieces. Koga then reveals that he can turn the remains of Dalk into an axe and the battle continues. Hitsugaya activates his Bankai and though Koga puts up a fight, he is soon grievously wounded and Hitsugaya leaves him. Back in another part of Seireitei, Uryū arrives to save Ran'Tao. Uryū engages Kariya and gains the upper hand early on. As the battle continues though, the Quincy Bangle begins to overheat and finally chips. Kariya takes the moment to attack Uryū, sending him into the air and then crashing down. As he prepares to finish the Quincy though, Ran'Tao jumps on Kariya and stabs him in the back with a special knife. Ran'Tao pleads for Uryū to fire an arrow at the two of them to take out Kariya once and for all and after some hesitation, fires an arrow straight at them. Uryū catches Ran'Tao and reveals he held back, but her Reiatsu begins to go out of control. Instead of finishing Kariya while he is injured, he uses the Quincy Bangle to absorb her wild Reiatsu and afterwards, the bangle finally breaks. Kariya goes to finish the two, but is interrupted by the arrival of Ichigo. Ichigo and Kariya clash before moving the battle. As they continue though, they are interrupted by Ichinose who attacks Ichigo. However, Ichinose then questions Kariya and turns on him. Kariya then runs his arm through Ichinose's stomach, sending him back and then killing him with his wind. Kariya then reveals the true form of his doll, Messer. The two clash again with neither gaining the upper hand. Ichigo manages to push the Bount back, but Kariya then states that he will show the true power of his doll and the wind coming from his doll turns to electricity. Kariya reveals his plan to Ichigo and Ichigo angrily questions what the point of killing everyone is. Suddenly, Ichigo's inner Hollow takes over for a second and lands a powerful blow on Kariya. Kariya tries to heal, but is unable to, figuring out that Ran'Tao's knife did something to him. Kariya prepares to blow up one of the Jōkaishō and sends a blast of lightning at it, but it is stopped by Byakuya's Bankai. Kariya soon runs out of power and begins using the Jōkaishō's power to enhance his own. Ichigo and Kariya attack each other again and Kariya sends a large blast of electricity at Ichigo, but Ichinose's Zanpakutō acts as a lightning rod and Ichigo is saved. The two then clash one final time and a large explosion occurs, ending the battle.
Following their battle, Kariya says it is a shame that he will not be able to see if Ichigo walks the same path as him. He then turns to dust and fades away. Ichigo's friends run up to him and congratulate him. Ichigo says that Kariya died all by himself with no one there for him. Rukia mentions that this may be what Kariya had wanted all along and Ichigo theorizes that maybe Kariya just wanted to end his eternal life. Ichigo and friends say their goodbyes to everyone in Soul Society and then head back to the Human World.