Endroll Back summary:

Following the suicide of Yuka, a victim of bullying, her brother Asaharu becomes disappointed in himself, and encounters an angel. The angel proceeds to offer him a deal: find his sister's murderer within three months in order to resurrect her. 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!