Field boarding school for sixth grade.Living together for 3 days and 2 nights, I discovered a side of my classmates that I didn’t know existed.Makino (played by Gohei Matsushita) made no secret of his annoying attitude, and Shinoya (played by Aoi Morikawa) looked surprised.

When the children were fidgeting in the extraordinary space, Mizumoto Hana (played by Konishi Nozomi) looked unhappy.Hana and the naughty child Fujino Kazuki (Ueda Rinto) who deviated from the route in the walk rally, as well as the girls in the class, could not integrate well.

What bothered Hana was an incident in July.The Chinese Valentine's Day decorations that the whole class worked hard to make were completely destroyed by someone after school.Although Kazuki is suspected of being the culprit, the real culprit is Hana.Hana had destructive impulses because of her loneliness.Kazuki knew who the prisoner was, but he kept this secret.But Hana was worried about whether Kazuki would tell others the truth, and she was also worried about it when she was in field school...

If his identity as the murderer is revealed, he will have no place in the class.Just like that, Hana impulsively pushed Kazuki into the river.Makino, who witnessed the scene, planned to confront Hana, but Kazuki and Hana escaped from the rescue room...!