Katsumi Matsunaga

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

Appearance
He has brown hair and brown eyes.

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' and hides it in classroom.

In Episode 8, after he learns that Reiko looked for him at the beach hotel, he went out to look for them. On the shore, Matsunaga had a chat with Reiko and the others. At the end of the episode, they witness Junta Nakao's death.

It is revealed in Episode 10 that the most important thing he did to stop the calamity was to accidentally kill a classmate (his name can't be heard because the tape's audio was altered by the calamity) who actually was the dead one. Katsumi, terrified and ran away. When he return the next day, the body disappeared and everybody forgot about that person. This action stops the calamity. But in time, even Katsumi forgets what happen in the class trip.

Trivia

 * In the original novel, Matsunaga is never seen and only has contact with Tomoka Mochizuki.
 * He is a smoker and drinker.