As Black Rock Shooter fights against a huge army under Dead Master's control, Yomi behaves strangely at school, cutting her hair in class, causing Mato to become concerned, even lashing out at Kagari. As Yuu becomes cautious of Saya's actions, Mato sees the battle between Black Rock Shooter and Dead Master in her sleep. As Mato visits Saya the next day, she tries to strangle her, leaving her confounded. After seeing the painting Yomi drew of her, Mato comes to realise that is because of her that Yomi is suffering. She soon discovers that noone in the basketball club remembers Yuu, soon finding her own memories of her to be a lie. Yuu then appears before her, telling her that the other world in her dreams is real. She explains how the people in the other world represent the sorrow upon their real world counterparts, and if they are killed, the person forgets about their attachments that caused them that grief, meaning if Dead Master is killed, Yomi would forget all about her. Offering Mato the chance to save Yomi without resorting to fighting, Yuu puts her into a deep sleep, sending her mind into that of Black Rock Shooter, only to find she had just killed Dead Master. The shock of this causes Black Rock Shooter's blazing blue eye to become purple, becoming Insane Black Rock Shooter. (thetvdb.com)