Tetsuo Takahashi

 is a main character in Demi-chan wa Kataritai.

A Biology teacher by profession, he holds an innate interest in demi-humans for their unique existence. Despite his curiosities regarding demi-humans, his gentle nature lead him to value their struggles and bonds in adapting to human society over anything else as time goes by.

Several demi-humans have taken interest in him as he does not display the more apparent reactions that most humans give when presented with demi-humans' unique physiology; or at the very least, he forces himself to hide his fear, lust, and other primal instincts for the sake of prioritizing these demi-humans' well-being.

A welcoming face, stocky build, and kind heart made him quite the reliable father figure to many that knows him well.

Trivia
His nickname, "Iron Man," comes from a pun based on his first name; in Japanese, "tetsu" means "iron" and "o" is usually used for "man" or "person", and this nickname is likely reinforced by the fact that he is built like a tank.

History
He attended the Musashino University of Science