The plot starts with a janitor/teacher (forgot which) where he was interested/curious abt the particular student who looks like a decent top student. He follows the student and saw him with the school delinquent. Things happen, the janitor/teacher saw the 'good' student having sx w/the delinquent and saw the tatoo of the yakuza in the back of the two students. Turns out the good boy the teacher/janitor thought is a successor of a yakuza group and the delinquent is the fiance.
The plot starts with a janitor/teacher (forgot which) where he was interested/curious abt the particular student who looks like a decent top student. He follows the student and saw him with the school delinquent.
Things happen, the janitor/teacher saw the 'good' student having sx w/the delinquent and saw the tatoo of the yakuza in the back of the two students. Turns out the good boy the teacher/janitor thought is a successor of a yakuza group and the delinquent is the fiance.