Oneshot. Hades-sensei is spending lunch-break with his students: Ashitaba, Fuji, Mimasaka and Kaburagi. Mitogawa-sensei, Niburu and Keiichi also pay them visit. Keiichi calls the students by numbers, so Mitogawa-sensei proposes to play a game in which they bet who 'student no.1' is. And so the petite woman announced "Well then, let's find out Itsuhito's no.1!"