After the hard-earned funds for their expensive high school class trip are stolen, sophomore Yuichi and his four best friends are kidnapped by Manabu, a surreal character from a creepy late-night anime show. The mischievous Manabu challenges the students to a series of mind games that the five must decipher and outwit in order to win back their trip funds, uncover the thief, and pay off a huge and mysterious debt.

Yuichi and friends reach the end of Kokkuri-san, uncovering dimensions of trickery in the Tomodachi Game that they hadn't imagined. When they move on to a second game, a socially destructive version of sugoroku, the group struggles to maintain balance as personal secrets are revealed and trust is stretched to its absolute limit.

The third game, Friendly Hide-and-Seek, begins. Rival Group K, bolstered by an apparent 'genius' strategist, proceeds with a clear numerical advantage. Eager to regain Yuichi's trust, Tenji volunteers to be Group C's hider, but the couple's plans are strained by the addition of a new female teammate, Mizuse Maria. Yuichi confidently tells Tenji to "just trust me and wait," but then doesn't return for days...