Sex Is No Laughing Matter (2008)

Mirume is a 19 year old college student who falls in love with Yuri, an almost 40 year old art teacher at his university. Yuri isn't your typical college professor, having a quirky sense of humor and unpredictable personality. When Yuri invites Murume to her studio, she playfully seduces the still naive 19 year old student. Things become more complicated when Mirume discovers that Yuri is married to a much older man....