Huh? Yuichi-kun Suspects His Friends? (E01)

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. (Crunchyroll)