High schoolers Mitsuha and Taki are complete strangers living separate lives. But one night, they suddenly switch places. Mitsuha wakes up in Taki’s body, and he in hers. This bizarre occurrence continues to happen randomly, and the two must adjust their lives around each other.

Defeating numerous villains in the abandoned area in Z-City but still having problems with rent money (and continued harassment from the landlady who says he's 3 months overdue), Saitama speaks with a shop owner who is being forced by a local gang to surrender his store's deed. Several other shops have gone out of business and his store is the last one; a conversation between the gang boss and one of his stooges reveal that the boss has had an impulse to buy out all the stores in the area to destroy them.