Onegai Teacher

A story mainly revolving around a tight-knit group of friends in high school and how they cope with several life-changing events that are never too far off from intimate relationships. The main character is a boy named Kei Kusanagi who suffers from a very rare disease which causes a comatose state referred to as a "standstill" whenever he is under severe emotional distress.

Note: The title was never "- sensei," the Japanese characters "ティーチャー" phonetically spell "teacher"