Cicada Boy.

Okawa Yuka is living out the daily motions of life but doesn't understand her reason to keep living. After a confrontation with a co-worker, she decides to end it all but fails when she stops herself from squishing a cicada. That cicada returns the favor by transforming into a man, named semi, for seven days because he thinks it will make her happy. The downside is, he has no idea how to live as a human.