Manabu-sensei acts as the guide for Group C's second round in the Tomodachi Game, specifically overseeing the "Backbiting Sugoroku" segment. While resembling the series' mascot Manabu-kun, he differs significantly in appearance, sporting long black hair and attire akin to a school teacher's blazer and tie, contrasting with the mascot's cartoonish spiky hair, yellow cap, and blue overalls. He conducts the game on a school rooftop, explaining its rules to participants. The game requires players to move across tiles by submitting cards exposing secrets about others. Steps taken correspond to the severity of the revealed secrets, with bonus points awarded for submissions that "vilify friends." Manabu-sensei emphasizes that each step forward incurs escalating financial penalties, starting at -100,000 yen and increasing to -500,000 yen. Crucially, he reveals that the first participant to reach the finish line shoulders the entire group's accumulated debt, a detail he withholds until after movement begins. Demonstrating manipulative tactics, Manabu-sensei suggests submitting blank cards to avoid betrayal but simultaneously warns that a single "traitor" submitting non-blank cards would jeopardize the group. He permits lies on cards but states that false submissions proven with evidence result in the liar being forcibly advanced toward the finish line. He frames betrayal and conflict as entertainment for an audience funding the game, whom he calls "Gods." His guidance explicitly encourages participants to "expose friends" and "push them to the metaphorical hell that is the finishing line" to avoid personal loss. His facilitation escalates tensions within Group C, exemplified by the third-round submission of a card exposing a fabricated love triangle, straining participant relationships.