Following his younger sister Yuuka's suicide due to bullying, Asaharu becomes despondent, only to encounter an angel. The angel proceeds to offer him a deal: find his sister's murderer within three months, and she'll resurrect Yuuka. However, nothing is done without compensation. With every mistake that Asaharu makes, his life expectancy will decrease. Is his sister's life more valuable than his own? The hunt for the criminal begins!