One fateful day, things escalate when Satou runs into Kojima in the restroom, leading them to share an intimate encounter that makes his imagination run wild for days after. Kojima is Satous Japanese language teacher with a reputation for being so ruthless that even school delinquents bow down to her. This means that two couples have to look for another place to stay. However, something went wrong with the room reservation, and as a result, only two double rooms are available. Second year high school student Ichirou Satou has always been an average person-that is, until he runs into some not-so-average situations with his teacher, Kana The Demon Kojima. The four couples who got together in the main series go on a joint trip to another city with an overnight stay and a sightseeing tour the next day. Nande Koko ni Sensei ga? follows the daily life of Satou and his teacher as they continue to meet under similar conditions, growing ever closer with each encounter. Kojima is Satou's Japanese language teacher with a reputation for being so ruthless that even school delinquents bow down to her. Second year high school student Ichirou Satou has always been an average person-that is, until he runs into some not-so-average situations with his teacher, Kana 'The Demon' Kojima.