Ayumu and co. take part in a flea market in which Haruna is challenged by Orito to earn the most money. Although Haruna has trouble making sales, the others pitch in to help. After the market closes, Ayumu accidentally drinks something that turns him invisible. Whilst invisible, Ayumu is tasked by Haruna to go into school during a physical exam and find a pendant one of the girls bought.

[Source: Wikipedia]