Junjou Karen

Tamiya, a student whose honesty tends to be so blunt that it gets him in trouble, has fallen in love with Shirasaka, a teacher from his school. He's an excellent teacher, very caring and popular among students, but because of his dark past, there seems no hope for Tamiya to win over his heart. In the past, Shirasaka had a relationship with Iogi, his senior on the track team, and they were both in an accident which was Shirasaka's fault. Iogi became seriously injured and was forced to give up his athletic dreams. Since then Iogi has used Shirasaka's guilt to keep him close. Is there any chance for Shirasaka and Tamiya to be together?

(Source: Storm in Heaven)