Before Masahiro and Kousuke's whirlwind romance in Hitorijime My Hero, there was Hitorijime Boyfriend—and now, the origin of one of manga's biggest franchises is finally revealed! Back in sixth grade, Kensuke had a falling out with his best friend Hasekura that still hurts three years later. Then, one day, Hasekura's suddenly back in Kensuke's life like nothing happened. What, exactly, is going on? And what will Kensuke do when Hasekura wants to take things to a whole other level...?