Mashiro's appearance is that of a young woman with hazel eyes. She wears a white bodysuit with orange gloves, boots and scarf, along with a set of goggles atop her lime green hair. Her overall style of dress is reminiscent of the costumes worn by the Tokusatsu superheroes in late 1970s Japanese television shows.
During her time in Soul Society, she wore the standard Shinigami robes, though her sleeves were very long. She also wore a pink scarf and a pair of glasses perched atop of her hair, which was wavier then.
Seventeen months after the defeat of Sōsuke Aizen and having returned to Soul Society, Mashiro's hair is much longer. She wears the standard Shinigami shihakusho, while keeping her goggles, orange gloves and boots from her time in the Human World. She also wears a custom made badge on her arm that has a 9 on it and the word Super.
Despite having formerly attained a position in the elite Gotei 13, Mashiro has very childish and immature mannerisms. She is portrayed as rather flighty and rarely takes note of the bigger picture around her. She is prone to throwing fits over the smallest of things, such as Orihime Inoue befriending Hachigen Ushōda or when Kensei insisted on following his subordinates into battle. Her childish personality frequently irritates her Captain Kensei, causing him to question why he kept her as a lieutenant at the time; he has noted she is capable of annoying him even while asleep.
She often calls Ichigo "Berry-tan" (Berry Boy in the English manga, Carrot-Top in the English dub anime), a play on Ichigo's name. She seems to be good friends with Hachi, instantly disliking it when Orihime befriends him.
In battle, she is somewhat more serious though, acting slightly like a superhero while attacking and after winning.
Approximately 100 years ago, Mashiro was the lieutenant of the 9th Division under then Captain Kensei Muguruma. She, along with Kensei and the 3rd, 4th, 5th, and 6th Seats of her division went to investigate the mysterious disappearances in Rukongai. She constantly complained about the fact that they had to investigate when they had no idea what it was that they were looking for, noting that a vanguard of 10 other investigators were already sent prior to their arrival. Her incessant whining only irritated Kensei, which caused his subordinates to have to hold him back to stop him from attacking her. Kensei plainly told her that she wasn't even asked to come along, and told her to just go home. She responded that she is his lieutenant, so she has to follow him. She then fell down on the ground and went into a temper tantrum, screaming about how hungry she was.
Kensei decided to ignore her, but was then startled by a Hollow attack. Mashiro, while not taking part in the battle, found 10 empty shihakushō close to where the Hollow creature attacked. Mashiro was unable to grasp the significance of her finding the shihakushō in relation to the mystery of the missing Shinigami. Kensei immediately realized that the ten empty shihakushō must have belonged to the ten members of the vanguard originally sent to investigate, and he sent his men to relay the situation and get help.
Later, Mashiro is sleeping soundly in the tent, completely at ease despite the day's events, much to the annoyance of Kensei, who couldn't fathom how she was able to sleep at a time of such tension. When Kensei tried to fix her garb so that she wasn't exposing herself, she caught his hand and mumbled, "Kensei, you perv" in her sleep, which made Kensei note that she is even annoying while asleep. Kensei was then alerted by a scream that his team was under attack by some unknown assailant.
When a team of captains and lieutenants were sent out to investigate the disappearance of Kensei's investigation team, Rōjūrō Ōtoribashi, the captain of the 3rd Division, received a devastating kick from behind by a Hollowfied Mashiro, which caused him to hurtle down into the ground below.Shinji Hirako, captain of the 5th Division called out to Mashiro, who took note of him and began to head towards him to initiate another kicking attack, which Shinji blocked with his Zanpakutō. Kidō Corps Lieutenant Hachigen Ushōda showed up just in time to stop Mashiro from attacking Shinji by using Bakudō #75: "Gochūtekkan" to restrain her. The investigation team gathered after the fight to talk about the situation. At that moment, then 12th Division Lieutenant Hiyori Sarugaki became Hollowfied herself. It was then that a darkness fell around the rescue squad and they were attacked by an unseen assailant.
After the attack, the assailant was found to be a masked Kaname Tōsen, Kensei's 6th seat, who was acting under the orders of Sōsuke Aizen. Aizen revealed that he was the one behind the disappearances and Hollowfication experiments. Just as Aizen gave the order to kill the Hollowfied Shinigami, 12th Division Captain Kisuke Urahara and Kidō Corps Captain Tessai Tsukabishi showed up and saved them from destruction. Aizen, Gin Ichimaru, and Tōsen escape and Tessai proceeded to use Forbidden Kidō to preserve and transport the Hollowfied Shinigami to the 12th Division barracks. In his lab, Urahara tried to reverse the process using his recent invention, the Hōgyoku. However, the use of the Hōgyoku was only partially successful, not having the desired effect of completely ridding the effected Shinigami of their Hollowfication, instead only halting the consummation of their souls by their inner Hollows for the time being.
The next day, Urahara and Tessai were arrested under the orders of the Central 46. The Hollowfied Shinigami were sentenced to execution as Hollows. Before any of their sentences could be carried out, both the Hollowfied Shinigami and Urahara and Tessai were rescued by 2nd Division Captain Yoruichi Shihōin, who brought them to a secret underground area. Once in the secluded area, Yoruichi revealed that she had also brought the prototype for a new Gigai that Urahara had been working on. Knowing what he must do, Urahara resolved to make ten Reiatsu-blocking Gigai to aid himself, Tessai, and the eight Hollowfication victims in their escape to the Real World, where they would attempt to find a way to undo the Hollowfication process.
Along with the other Visored, Mashiro is at their warehouse when Ichigo Kurosaki arrives in order to ask them for help in controlling his inner Hollow. Love comments that Ichigo is scared and Mashiro asks what he is scared of, to which Kensei replies that Ichigo is afraid of his inner Hollow. Later, Mashiro asks what Hiyori is doing when she walks toward the fight between Shinji and Ichigo.
Mashiro is next seen asking an exhausted looking Hachi, who is trying to keep up the barrier around the fight, if he is alright, to which Hachi responds no. Mashiro then witnesses Ichigo's inner Hollow surface and nearly choke Hiyori to death, and she, as well as the other Visored, quickly restrain Ichigo before he can kill Hiyori.
Mashiro later returns from shopping with Hachi, while Ichigo is training by himself and the other Visored are just sitting around. Mashiro tells Love that she bought box lunches and asks him if he wishes to eat now. She then notices the argument Ichigo has been having with Hiyori, and proceeds to ask Love what is wrong with Ichigo. Love responds that apparently Ichigo isn't happy with doing the training exercise that Hiyori has set up, because Ichigo thinks that she didn't really clearly explain it or why it's necessary.
Mashiro later goes with the other Visored down into the underground training area. Mashiro waits with the other Visored while Ichigo's inner Hollow emerges to take control over his body. When Mashiro asks whether they should take away his Zanpakutō, Love states that it would be pointless as doing so would needlessly increase the radius of destruction. When Ichigo defeats his inner Hollow and gains control over his body he passes out. Mashiro asks Hachi if Ichigo is okay, but he tells her to be quiet.
While Ichigo is training with Hiyori, Kensei is timing how long he can maintain his Hollow Mask. Mashiro asks why it is that Ichigo has to do this, to which Kensei explains that he has to practice in order for him to maintain his Hollow Mask, telling her that she had to do it too. Mashiro simply tells him that she didn't, causing Kensei to become irritated, but Shinji tells him it's true. Since Mashiro could maintain her Hollow Mask for 15 hours right from the start, she alone has never had to undergo the Hollow retention training. Kensei admits he had forgotten all about it. Mashiro begins to make fun of him, enraging him even further and causing him to have to be calmed down by Hachi. Hachi becomes alerted when he detects someone has slipped inside the barrier protecting the Visored compound, and the other Visored are surprised at the possibility.Orihime Inoue shows up and is revealed to be the one who broke into the barrier. Hachi and the other Visored are shown to be quite shocked that a simple Human could perform such a feat.
Later, Mashiro is shown having a temper tantrum because Hachi is helping Orihime fix her Tsubaki power, complaining that she finds Orihime to be annoying. This causes Kensei to once again become irritated, but they are both calmed by Rose, who states that it is very rare to come across others with powers similar to theirs, and that he feels as though their family is growing.
Mashiro is later seen leaving the warehouse with the other Visored to fight in the upcoming conflict.
Mashiro stands ready for battle as the other Visored draw their Zanpakutō and attack the Gillian. Mashiro displays her increased physical strength by defeating a cadre of four Menos using her "Mashiro Kick" to easily destroy their masks.
After Kensei kills the last Gillian, Mashiro complains that she was going to get the last one, and Kensei tells her to shut up and stop complaining because he is going to give her the big one. Mashiro looks over to Hooleer and is happy, telling Kensei she loves him for it as she rushes off to face the creature. She confronts Wonderweiss Margela face to face, who is seated in front of Hooleer. But instead of attacking him she uses her " Mashiro Super Kick" on Hooleer, instantly killing the huge Hollow, surprising Wonderweiss.
As the smoke clears Wonderweiss is shown disturbed at the death of his pet, and he opens his mouth to fire a Cero at Mashiro. Before he can fire the Cero, Mashiro is seen through the clearing smoke, and Mashiro kicks him with both legs, hitting him feet first square in the face. Wonderweiss goes crashing down into a building below and is seemingly knocked unconscious. Mashiro screams 'Victory' while Gin watches in amusement at Wonderweiss's apparent defeat.
Mashiro looks up and watches as Aizen attacks Tier Harribel, stating her surprise that he "killed" the last Espada. Her attention diverted by Aizen's attack, she isn't watching when Wonderweiss revives, prompting Kensei to yell at her to get her attention. She plainly tells him that she knows and kicks Wonderweiss in the face, sending him flying blocks away into the various buildings. Kensei tells her that fighting this level of opponent will quickly exhaust her. He warns her that she better take off her mask before she runs out of time. Mashiro tells Kensei that he is dumb and that he has no idea how long she can stay Hollowfied. She states that she can keep her mask on for 15 hours and thus she can keep her mask on all night.
Wonderweiss goes flying toward Mashiro to attack her, but she tells him to just give it a rest as she grabs him by the face and slams him into the ground. Wonderweiss shrugs the attack off and lets out a loud cry. He reaches for Mashiro and grabs her by the scarf, catching her off guard as he throws her many blocks away. Mashiro stops her momentum and becomes upset that Wonderweiss ripped her scarf, then the two lunge at each other, with Mashiro promising to make him pay. She engages a Mashiro Super Cero firing a Cero from the arc of a kick. Before the Cero can reach him Wonderweiss erases it with another loud cry, but this doesn't deter Mashiro, who gets in close to attack him. However, before she can attack, her mask shatters and falls apart, with Mashiro in disbelief that her time is up. Wonderweiss takes the opportunity to attack, landing brutal punches to Mashiro's face, but before he can continue, his hand is stopped by Kensei. Kensei then takes Mashiro over to the nearest building and lays her on the rooftop. Mashiro asks him if he is going to avenge her, laughing as she asks this. Kensei tells her not to be so happy, because what happened to her was her own fault for ignoring his warning. He says he doesn't want to avenge someone like that, but rather simply wants to give Wonderweiss a taste of his fists, and activates his Bankai.
The Thousand-Year Blood War arc
While in a forest outside Seireitei, Captain Kensei Muguruma hosts a training session for Shūhei Hisagi. Kensei then commands Shūhei to use his Bankai stating that they are in need of people capable of using Bankai in case of Kensei's Bankai being stolen. Mashiro leaps out and at Kensei's command, she dons her Hollow mask. As Shūhei protests, Mashiro attacks him and tells Hisagi that he should not disobey her as she is the "super lieutenant."
Powers & Abilities
Hakuda Master: Mashiro's primary method of combat revolves around various powerful kicks, which she excels at. While in the advanced state of Hollowfication, Mashiro proved to be quite aggressive as well as highly proficient in hand-to-hand combat. She demonstrates her skill and agility in this area by launching a devastating attack against 3rd Division Captain Rōjūrō Ōtoribashi.
Mashiro Kick (白キック, Mashiro Kikku; Japanese for "White Kick"): Mashiro perform a front kick. This technique proved powerful enough to shatter the masks of multiple Gillians while Mashiro was wearing her Hollow mask.
Mashiro Super Kick (白スーパーキック, Mashiro Sūpā Kikku; Japanese for "White Super Kick"): After crouching, Mashiro performs a powerful upward kick. This technique was potent enough to instantly kill the giant Hollow creature Hooleer while Mashiro was wearing her Hollow mask.
Mashiro Drop Kick (白ドロップキック, Mashiro Doroppu Kikku; Japanese for "White Drop Kick"): Mashiro drops feet-first downward upon her target from above with enough force to crater the ground and destroy the surrounding area upon impact.
High Spiritual Power: Mashiro possesses Lieutenant-level Reiryoku. Being a Visored, Mashiro possesses a dual type spiritual energy, part Shinigami and part Hollow.
Mashiro's Zanpakutō is an average sized katana with a green hilt-wrapping, rectangular tsuba with circles on each corner of the rectangle, and silver sheath. During her Shinigami days she wore it by her waist like many others, but as a Visored she carries it around in her hands. Excluding holding down the Hollowfied Ichigo to prevent him from killing Hiyori, she has never used her Zanpakutō. While fighting the Gillians in Fake Karakura Town, she discards her still sheathed Zanpakutō and engages the Gillians unarmed.
Hollow Mask: Her Hollow Mask takes the form of a hornet or bee. Compared to the other Visored, Mashiro is uniquely in touch with her inner Hollow; from the start of her Hollowfication, she was able to maintain her Hollow Mask for fifteen hours without practice of any kind, which in turn meant that she did not have to train to maintain the mask like her fellow Visored. However, this seems to be under unique circumstances outside of battle. Against opponents of higher caliber, her time limit is considerably shorter, proven when her mask shatters during her battle with Wonderweiss Margela.
Power Augmentation: While wearing the mask, Mashiro's Hollow powers supplement her Shinigami powers, giving her a vast increase in both strength and speed. The transformation gives her legs great strength and speed. While in Visored form, her attacks seem to focus almost exclusively on powerful kicks.
Enhanced Strength: This increase in power and style is carried over to her Visored powers, as shown by the fact that she can break a Gillian mask and destroy Hooleer, both in a single kick.
Enhanced Durability: With her mask on, Mashiro becomes more durable, shown when she is thrown across several city blocks and comes out from the attack relatively unscathed.
Mashiro Super Cero (白スーパー虚閃 (セロ), Mashiro Sūpā Sero): Mashiro can fire a very fast lime-green Cero by kicking in the air towards her target. The Cero is wide and follows the arc made by her leg during the kicking motion.
Hollowfied Form: When transformed into a Hollow, her mask remains the same as in her Visored form, instead of covering her entire head as it usually does with a normal Hollow transformation. Her legs are transformed, gaining an insect- like appearance.
Enhanced Speed: Her transformation allowed her to possess increased speed.
Enhanced Strength: Her transformation allowed her to possess increased strength.
(To Kensei Muguruma) "Bahhhhhh~~! What are you, Kensei, stupid~? How long d'you think I can stay in Hollow form for, huh?! It's fifteen hours, okay? Fifteen hours! I could stay like this right into the night if I wanted to!"