Battle Royale: v. 10 by Koushun Takami
Shuuya walks into the dining room to find all the girls except Yuko dead. The tragic deaths of her friends has sent Yuko further over the edge. She climbs to the top of the lighthouse as the madness takes over her mind, ignoring Shuuya's pleas. Realizing she was wrong about Shuuya, Yuko throws herself off of the lighthouse. Shuuya tries to catch and hold her, but she slips free and dies on the rocks below. The events with the girls behind him, Shuuya heads out to find Noriko and his other buddies only to be confronted by more gun-wielding classmates. Will he survive? How will he react to the death of his good friend, Mimura? Have Noriko and Shogo stayed alive long enough for the three to be reunited?