A teenage girl that was introduced in chapter 18 where she returned Keita's acceptance letter when she found her dog trying to bury it in her yard. Out of a combination of stress from believing he did not get in to the relief he found out he did get in, Keita hugs her out of the blue. After that action she has shown an attraction towards Keita, often blushing when they talk and feeling very comfortable when he hugs her, but overall states she has nothing to do with him. Though it is obvious she is attracted to him, keeping her distance because of his sisters as well as her own inexperience being around boys, even fantasizing him raping her and experiencing an orgasm from him giving her a piggy back ride. Even though she does not go after him, his sisters still see her as a possible threat for Keita's heart. It is noted from Keita that she has a bigger bust than his sisters when he recalls the first hug they shared. She is currently in Gakushū Senior High and in the same class as Keita. People often mistake her being involved with Keita and will most of the time become caught in the cross fire of many of the twins' antics (which she comments on in chapter 25). She is the only girl Keita gets nervous around, suggesting he might have feelings for her. She has a weak bladder and occasionally wets herself, including once in front of Keita, but he promises to keep it a secret.  (Source: Wikipedia)

Keita has two older step-sisters, Ako and Riko, but since they aren't related by blood, they love him in a lustful way. After a mishap at school, Ako and Riko finally confess their love to him. Keita dislikes the thought of seeing them other then brother and sister, but as he tries to enter the same school as his sisters, he slowly becomes attracted to them. 
(Source: Anime News Network) 
 
Note: The first episode was aired as an online preview on Bandai Channel between 25th and 26th of March 2010. The regular broadcast started on April 5.

Keita is studying hard for a high school entrance test, but his two beautiful elder twin stepsisters are a constant distraction. Though they mean well, Ako and Riko are also extremely sexually assertive and interested in Keita. At first, he fends them off, but little by little, with each kiss, Keita becomes close to both twins until a forbidden love triangle develops. Will taboo-breaking love bloom between two of them... or will Keita at least get into high school?! 
(Source: Discotek Media)

Keita has two step-sisters who love him in a lustful way and have no problems expressing it, they even are in competition about that. Much to the laughs of his friends, he endures it but when one day they come to his school to give him his lunch, he gets annoyed and explodes on them, then they confess their feelings for him in front of everyone and leave. Feeling sorry he chases after them and says that he'll study hard in order to get in the same high school as them. 
(Source: MangaHelpers)

Miharu Mikuni