A disgraced ex special forces agent turns to a demon that offers him a job as a soul hunter. Chaos e

After wandering a ruined city for years in search of food and shelter, two siblings find their way into one of the last remaining buildings. Inside, they find a man who will make them a dangerous offer to survive the outside world.

中学3年级的冬天，因为某件事而放弃了水球的主人公清水凑。升入高中的他，以一个约定为契机，与在那里遇到的伙伴们开始了水球比赛。但是，在弱小的水球部里，各种各样的困难在等待着他们。