Sensei no Susume

With God no longer alive, angels in heaven have begun the search for a new deity. Rain, an angel, is one of four candidates selected for the role, despite his hesitation. Alongside the other candidates, Rain descends to Earth for a year to undergo a test that will assess their suitability. Each is allowed to reveal their true identity to one human. Natsume Shirou, a high school student aspiring to be a teacher, is chosen by Rain to assist in this task. The challenge requires them to nurture a lifeless, emotionless "baby" and develop it into a being as human-like as possible.