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.

Yuichi, who hasn’t left the starting point in the two days since the game began, suddenly announces his desire to switch to Group K. The Group K members, puzzled by Yuichi’s apparent intention to abandon his hiding teammate, ask their Captain to decide whether or not to let Yuichi in. Meanwhile, Tenji, who has stayed in hiding and trusted Yuichi all along, is finally reaching his physical breaking point.

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