Fukase

A long-time delinquent who is in his 30's, has IQ of 180 and had a strange past. He is popular among delinquents due to his tendency of targeting popular students while manipulating others to do his dirty work.

He harbors interest to Sakamoto and decides to play a "game" with him in throwing him out in school during the cultural festival which he is unsuccessful. During the graduation ceremony for the third graders, Fukase manipulates Acchan into attacking Sakamoto but once this fails, he was bested by Sakamoto and the whole school's delinquents into his own graduation. Finally moved on by Sakamoto, he was never to be shown at the school ever since and is currently working as a surfer at a nearby beach.
(Source: Wikipedia)