Tetsuo Takahashi  

Iron Man, 高橋 鉄男

The main character in this story is a biology teacher who shares an interest in the subject of Demi. He has a bulky build and is sometimes referred to by his students as "Iron Man" due to his name and physical appearance. Despite being fascinated with Demi, he occasionally faces challenges related to their teenage years and identity. As he gains more knowledge about them, he tries to support them in any way possible.