Katsumi Matsunaga

He is a Yomiyama North Middle School alumni from the 3-3 class of 1983.

Plot
After graduation, he moved to Tokyo to pursue his studies. He became a banker but dropped out after a few years, and returned to Yomiyama to help with the family business. During 1983, he managed to successfully stop the calamity in class 3-3; the only recorded case of the phenomenon stopping halfway through the year. Afraid he would forget his findings, he recorded his theories and confession on a tape for the following years' students to find.