Otoha Kohinata is a supporting character in the anime Happiness!, which adapts a visual novel set in the magical town of Mizuhozaka. She is the mother of the Kohinata household: the biological mother of Sumomo Kohinata and the stepmother and foster mother of the main character, Yuma Kohinata, having entered his family by marrying his father, Taigi Kohinata. Yuma's biological mother, Suzuri Minagi, was Otoha's close friend from their school days, so Otoha's place in the family is rooted in a long personal history. Although she is not Yuma's birth mother, she raises him as her own son and is the figure he calls mother.

Within the story's setting, the private Mizuhozaka Academy, Otoha runs the Oasis, a cafeteria on the school grounds that serves as a gathering place and resting spot for students. The students regard her as a mother to all of them, and the Oasis is frequently used as a warm, welcoming space. At home she is equally dependable, handling cooking, laundry, and all other household duties with ease, and she carries her domestic responsibilities with genuine skill.

Her personality is often described as unorthodox. She rarely behaves the way a mother of two children might be expected to, and her playful, mischievous energy is closer to that of her daughter's generation. Her appearance matches this liveliness: she has a youthful, baby-faced look and can easily be mistaken for a student at first glance, yet she still carries the subtle aura of an experienced adult, which makes people instinctively want to be coddled by her. Her youthful look and teasing charm have also made her a popular and well-liked figure in the local shopping district.

Her motivation is centered on caring for the people around her. She works to keep her own family comfortable and happy, and she extends that same maternal care to the students who come to her cafeteria, running the Oasis as an expression of her nurturing nature.

In the anime, she functions as a recurring supporting presence who anchors the domestic side of Yuma's life. Her relationship with her daughter Sumomo is lively and affectionate, and her bond with Yuma is defined by steady, quiet devotion. Her connection to Suzuri ties her to the family's past and its connection to magic, but her own strengths are domestic rather than magical: her notable abilities lie in cooking, housekeeping, and managing the Oasis with warmth and efficiency. Her character is not the focus of any major personal transformation over the course of the series; instead, she remains a constant, stabilizing figure whose backstory, including her friendship with Suzuri and her decision to marry into the Kohinata family, explains her unwavering dedication and gives depth to her maternal role.