Editing Please Twins! (section)

===Supporting characters===
;{{Nihongo|Haruko Shidō|四道 晴子|Shidō Haruko}}
:{{Voiced by|[[Ryoko Shintani]]|[[Kim Mai Guest|Therese Nguyen]]}}
:Haruko is Matagu's younger sister and is usually very bubbly and [[hyperactive]]. She has a very immature personality and, while she acknowledges that her brother is a pervert, she seems completely oblivious to such mature matters. She attends class 1A. She, Akina Sagawa and Futaba Mashita greet Miina and Karen on their first day of school.

;{{Nihongo|Kousei Shimazaki|島崎 康生|Shimazaki Kōsei}}
:{{Voiced by|[[Kenichi Suzumura]]|[[Crispin Freeman]]}}
:Kousei is Maiku's only real friend at the beginning of the series. He sits next to Maiku in class, and often becomes a bit too flirtatious with Maiku, usually resulting in him getting punched or slapped away by Maiku. For example, when Maiku reveals he needs money, Kousei actually tells him that if he stayed with him for a night, he would pay as much as Maiku wanted, resulting in him getting slapped. Despite Kousei's flirtations making Maiku uncomfortable and Maiku hitting or slapping Kousei in response, the two are close friends throughout the series. Kosei is assumed by his peers to be Homosexual, by his many openly flirtatious interactions with Maiku. However, it's eventually revealed that Kousei is still in love with his ex-girlfriend, Tsubaki, revealing that he is actually bisexual. Kosei eventually manages to work out things with Tsubaki and they get together again in the end.

;{{Nihongo|Tsubaki Oribe|織部 椿|Oribe Tsubaki}}
:{{Voiced by|[[Michiko Neya]]|[[Jessica Straus]]}}
:Tsubaki is the vice president of the student council and usually has a very serious personality. Intelligent and outgoing, gifted with a busty figure and possessing a more mature personality than the 'twin' girls, she is a source of concern for Karen and Miina as being an obvious rival for Maiku's affections. Her attempts to interest Maiku in a relationship, however, are met with Maiku's tacit plea for just friendship. It is not until she confers with (the much older and wiser) Ichigo that Tsubaki realizes that Maiku cannot engage in any casual romantic relationship due to both his obligations to his new-found 'family' and his own forcibly matured, responsible nature. This causes Tsubaki to gain a higher degree of respect for Maiku, and to focus her attentions on the one person she once thought too forceful in expressing his affection for her, Kousei Shimazaki. In the anime she had objected to Kousei putting his hand on her breast when they kissed for the first time. In the light novel she had been psychologically traumatized when her brother died at a young age and she had been trying to fill a void, first with Kousei, then with Maiku. In the anime, however; Tsubaki managed to work out things with Kosei and they get together again in the end.

;{{Nihongo|Yuuka Yashiro|社 裕香|Yashiro Yūka}}
:{{Voiced by|[[Miyuki Sawashiro]]|[[Julie Maddalena]]}}
:Yuuka is Miina's friend from middle school. She appears at the end of episode 9, recognizing Miina and recalling the history that Miina has been trying to put behind her. Miina comes to terms with it in episode 10, and Yuuka is seen again at the beginning of episode 11. In the light novel this section of the ''Please Twins!'' story is entirely rewritten and Yuuka is omitted, replaced with Yukiko Kachofugetsuin, Karen's rival in playing the piano.