亡くなった母親の代わりに保育園児の弟「愛」の育児をしている中学生の「良太」。良太は自分を犠牲にしながらの家事や育児に悩む。そして片時も自分から離れない弟が憎く思えてしまう。やがて憎しみは殺意へと変わり…。育児のストレスで良太は徐々にオカシクなり始める。果たして壊れているのは良太なのか…?それとも…。
When their mother dies, junior high school student Ryota takes care of his toddler brother Chika and their home. Overwhelmed by all the work, he begins neglecting himself. Without any time to himself, Ryota comes to resent his little brother and soon the resentment turns into murderous thoughts. Little by little the pressures of childrearing make Ryota lose his mind. But is Ryota truly the issue? Or…