Sensei no Koto, Kusugutte Ageru

Shuuma Aguri isn't like other high school boys. He doesn't get into sexual talks with his friends, and he sits alone. While he does have a secret fetish, he keeps it to himself—after all, who would willingly talk to a guy with a tickle fetish?

The only solace he has in his life is Anzu, a girl he met online who herself has a desire to be tickled. The two decide to meet up one day, only for Shuuma to find out that Anzu... is actually his teacher, Maiko Ogura?

(Source: MU)