Nothing is known about his current appearance. In his youth he had dark hair and was missing a front tooth, wearing a simple T-shirt and sneakers.
For what little was seen of Kotaro as a child, he seemed like a relatively happy and normal boy, who had a close relationship with his mother.
However, after her death Kotaro developed a deep resentment towards his mother, feeling as though she selfishly abandoned him for the sake of strangers. This resentment eventually grew into a hatred for all heroes, viewing them as selfish individuals whose actions only served to harm their own families.
As a result of this hatred, he showed disdain for anything hero related and became both physically and emotionally abusive towards his own son whenever he show any interest in heroes. This is seen again when he attacked his child for finding the picture of his grandmother and condemning her memory. Ironically, he started doing the very thing he believed all heroes were guilty of and instilling his son's future hatred of heroes and society.
However, in spite of his cold attitude, he wasn't completely heartless, eventually questioning his own behavior towards his family and expressing remorse for his acts. Despite his resentment of his mother, he expressed tears when on to a picture of her with him as a child.
Kotaro Shimura is the son of Nana Shimura. He was placed into foster care by his grieving mother when his father died. Nana also prevented her close friends from searching for him before her own death.
He later married and had a daughter named Hana Shimura and a son named Tenko Shimura (alias: Tomura Shigaraki). He was killed after Tenko lost control of his Quirk. The only thing that remained of him was his disembodied hands that his son currently wears as his villain costume. His lonely son would go onto become the successor of All For One, the very villain who killed his mother, Nana Shimura.
- ↑ 1.0 1.1 My Hero Academia Manga: Chapter 222.
- ↑ 2.0 2.1 My Hero Academia Manga: Chapter 227.
- ↑ My Hero Academia Manga and Anime: Chapter 95 and Episode 50.