high school and becomes a singing idol. The youngest of the three half-sisters. She is three years old and attends daycare. She is the biological daughter of Yuri and thus the only one of the three girls who is directly related to Yuuta. She is very friendly and unafraid of strangers. She sometimes mispronounces words, often leaving out certain consonants. She normally addresses Yuuta as Oji-san but has trouble with the "j" and "s" sounds so it comes out as Oi-tan (little uncle). She is a fan of the heroine anime, Luna Luna Seven. Whenever Hina mentions her parents' names, Yuuta and the elder sisters did their best to keep her cheerful till she emotionally accepts they're in heaven. In the OVA, she begun her second-grade in elementary school and speaks clearly. Street Observation Research Society A second-year student at Tama University School of Literature. She is the only female member in the Street Observation Research Society. Every time Sako has perverted thoughts or is crude, she beats him with a giant paper fan. Despite being very attractive, she does not reveal her emotions easily and dislikes talking with anyone except for Yuuta. Raika is a very good cook, particularly in Japanese cuisine and likes to tease Yuuta. She especially loves cute things, and upon encountering them her personality changes. This also applies to Yuuta's nieces including Sora, who does not like Raika because she is jealous of Raika's relationship with Yuuta; ironically see her a maternal figure. A first-year student of Tama University School of Literature. He is a good friend of Yuuta's and a womanizer. He insists that his house is only for entertaining girls. As a result, he almost never stays at his home and instead spends time at Yuuta's apartment, or at one of his affairs' places. He is however a very caring friend and will help out with chores on his own initiative. He also helps Yuuta keep Sako away from his nieces and has a soft spot for Miu. A third-year student of the Tama University School of Literature. He is the President of the Street Observation Research Society. Sako has been a third-year in the university ever since Raika enrolled. He is a lolicon and wears thick glasses. He once told Raika that "Love is justice. Love is the strongest." to justify his lolicon fetishes to which Raika later agrees. Despite this she