Suzumushi

Suzumushi is the name of the Zanpakuto of the former captain of The 9th Division, Kaname Tosen. When a woman very special to him died because her husband killed her for scolding him, because he killed a comrade over a pointless arguement, Kaname took her sword (Suzumushi) and vowed to follow the path with the least bloodshed, hence his defection of the Soul Society.

In it's Shikai form Suzumushi is just like a regular sword with the exception of the ring on the side which activates it's bankai. Suzumushi litterally means 'Cricket'. Suzumushi's regular release command is 'Cry'. In this form Suzumushi sends a highly pitched sounds that knocks opponents unconscious, which fits Kaname's personality very well. Unlike most shikai's Suzumushi has a second release command, 'Smash His Limbs" in which Suzumushi vibrates momentarily and then makes a circle of blades that attack it's opponent. This form is called Benihiko which means Crimson Flying Locusts.

In it's Bankai form Suzumushi takes the form of Enma Korogi, which means Devil Cricket. This form also stays the same as a regular zanpakuto that has not been released, except without the ring on the side( because activating Enma Korgi causes the ring to disapear). Enma Korogi creates a giant dome that is around the size of a house in the Seretei, anyone in this dome loses all of their senses (touch, sight, smell, hearing, and taste.) This means that the opponent cannot fight back or even know where the user is. But, what makes Kaname invulnerable to this, is also Enma Korogi's weakness. The weakness is that anyone who touches the hilt of Suzumushi becomes immune to all of it's effects. But if the opponent were able to get a hold of the hilt they would regain all of their senses, as demonstrated in Kaname's battle with Kenpachi Zaraki.