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.

Backed into a corner by Yuichi's plan, Tenji is forced to confess that he applied to play Tomodachi Game. Yuichi spells out the traps he set to smoke out the traitor and reveals that he had been manipulating the game from the start. The second game then reaches a breathtakingly unexpected conclusion.

After clearing Bad-Mouth Sugoroku, Yuichi and Tenji find themselves trapped in a dark cave for three days. During their isolation, Tenji makes the shocking revelation that he had already experienced a Tomodachi Game in the past. Meanwhile, a team of new opponents lies in wait outside, anxious to challenge the two partners to a grueling third game.

Yuuichi goes to help Kokorogi knowing it will be very dangerous, but things could turn out worse than imagined.