Hanjirou is a 23 year old math teacher—young, handsome, cool.. and a sadist. His teaching methods are surprisingly violent and he's armed with a whip and knives that are regularly put to use. But has Hanjirou met his match in the form of two students—the love-struck, odd Umi and the calm, collected Torosu? Included one-shots: Volume 1: Akai Chapeau Volume 2: Lemon Kajitta? Volume 3: Lemon Kanjichau