Yuu Aikawa

Honest, straightforward, and friendly. His childhood friend is Mitsuki, whom he cares a great deal for, and he takes it upon himself to protect her at all costs. Mitsuki is also the only person that Yuu completely trusts within the group. Yuu found himself inside the hospital after receiving a blow to the head from a wrench inside the bathroom at the karaoke bar. He also seems to be the only person who has caught a glimpse of the wolf. He's the only one who doesn't have a bar code tattooed on his skin which, the group discovers, are the keys to unlocking the network of doors keeping them trapped in the building. When his lacking a bar code is revealed, he is accused of being the wolf and is restrained for a time while the atrocities unfold around him, all the while maintaining his innocence. The story unfolds mainly from Yuu's perspective, and since he is very righteous and the only individual, besides Mistuki, who doesn't throw accusations around, it is safe to assume he is the main protagonist. Whenever someone in the group dies, Yuu takes it very hard, and often times winds up blaming himself in some way.