My Husband Is a Fitness Instructor, and All the Students He Trains Are Female Students.

The Protagonist Is a Substitute, Who Is Cruelly Abandoned, and Is Later Diagnosed with a Terminal Illness, Leaving Him Disheartened.

Later, they felt very guilty and tried their best to compensate him, but he did not accept it. Note (No heroine!!! No heroine!!! No heroine!!! Say important things three times)