Mrs. Yuigahama (由比ヶ浜夫人 Yuigahama fujin) is the mother of Yui Yuigahama.
Mrs. Yuighama seems to be a kind, lenient and friendly woman being mostly like Yui Yuigahama herself. They often make similar facial expressions.
Mrs. Yuigahama was first mentioned in a call, which interrupted Yui Yuigahama as she attempted to confess her feelings to Hachiman Hikigaya and Yui hurried home after her mother did something. She was formally introduced in Season 2 Episode 13 where she brings tea for both Hachiman and Yukino Yukinoshita who came to their house with Yui. In Season 3 Episode 9, she helps Hachiman and Yui bake fruit tarts for Komachi. In Season 3 Episode 11, she comforts her daughter after Hachiman indicates to Yui his feelings for Yukino Yukinoshita.
- The surname Yuigahama means "reason, case, cause" (由) (yu), "comparison" (比) (i) and "beach, seashore" (浜) (hama).
- Mrs. Yuighama already knew Hachiman Hikigaya by his nickname "Hikki", mentioning how Yui Yuigahama is always talking about him causing Yui to become highly embarrassed and push her out of the room.
- She also recognized Yukino Yukinoshita as "Yukinon" and asked Yui if she is required to prepare the futon for Yukino for the night stay, indicating that Yui freely talks to her mother about her daily basis. Yukino is openly envious of Yui's free relation with her mother.