Hiromi Shiota

Initially, Hiromi is portrayed as Nagisa's antagonist, being extremely controlling of Nagisa's life. She forces him to keep his hair long and makes him wear feminine clothing despite his aversion to it. When angered, she erupts in a violent rage, such as when she angrily yelled at Korosensei. Later, however, she becomes more lenient with Nagisa, especially after her son saved her life from an assassin hidden to attack Korosensei. Since then, the two seem to be on better terms.

She has been described as "pretty, but strict-looking." She has short, dark hair and is said to bear a strong resemblance to her son. In the anime, her hair is shown as dark navy blue, implying that Nagisa inherited his blue hair from her.

She revealed that her parents often forced her to study and that she was never able to dress herself. At some point, she met and married Nagisa's father (who only appears in chapter 178), and she became pregnant with his child. Due to her own "controlled" childhood, Hiromi wished to have a daughter so she could live the life she had desired through her. However, she had a son, Nagisa, instead. Despite having a son, Hiromi still tried to live the life she desired through him. Her methods included keeping Nagisa's hair long and occasionally forcing him to wear dresses.

According to Nagisa, it was Hiromi's controlling and semi-psychotic temperament that led her father to distance himself. On the few occasions when Nagisa brought some of her friends (like Karma and Sugino) home, Hiromi adopted a civil, but cold, attitude, leading Sugino to think of her as a strict mother.