Kôkô kyôshi: Torokeru kaki kôshu

高校教師 とろける夏期講習

Also known as 数学教師 絡み付く方程式, Sûgaku kyôshi: Karamitsuku hôtei shiki

On the last day of the term, Akane, a private high school math teacher, engages in a passionate tryst in the classroom with her lover, an English teacher named Sudo. However, she is devastated to learn that Sudo's wife is pregnant...