|Age|| 16 |
17 (as of Chapter 75)
|Eye Color||Raw Umber|
|Relatives|| Mr. Suminoe (step-father)|
Mrs. Suminoe (mother)
Ako Suminoe (sister)
Keita Suminoe (step-brother)
Disciplinary Committee Member
|Manga Debut||Vol. 1, Ch. 0|
|Anime Debut||Ep 1, OVA 0|
|Voiced By||Yukio Tatsumi|
Riko Suminoe (住之江 りこ, Suminoe Riko) is a 17 year old, second-year high school student. She is the youngest twin and the second step-sister to Keita. She is also one of the main character of the series.
Unlike Ako, Riko is less academically accomplished. Riko gets worse grades than Ako in her studies, thinking passing tests is dependent on luck, but is very active in physical activities; she sometimes helps out with various sports clubs that need a temporarily player for training. Riko is a terrible cook, unlike her sister. She has a habit of answering truthfully but very bluntly, causing everyone else to jump to conclusions, even one time almost stating that she and her sister wanted a computer solely for porn. She is much shyer in person than her sister, as she cannot kiss Keita in front of anyone else; Miharu Mikuni states that Riko has more common sense than Ako.
She is the head prefect (student in charge of punishing other students) on the disciplinary committee at her school, where she uses a shinai to punish the students. In school she is known to have a stricter personality, yet just like her sister will abuse her authority to get Keita alone with her.
She is also the more manipulative of the twins, as clearly seen in chapter 48 where she uses just the right moves to seduce Keita. Yūzuki Kiryū also notes this when she saw them kissing, stating that Riko is in complete control of Keita. However, she only shows this “special” nature when she is alone or with only Keita.
Ako - Her twin sister and rival for their step-brother's affections. She is jealous of Ako's homemaking abilities, and at times both girls will fight with each other in order to win their step-brother's love. However the two of them are always united in opposing another girl who's vying for Keita's heart.
Keita - Known as "Keita" to her Riko is very much in love with her brother. Unlike Ako she is more lustful in her interactions with Keita. She is very manipulative and knows just what to do to get Keita turned on. Once his inhibitions are released Keita is known to turn the tables on Riko; while she enjoys his domination of her, he has been known to be too much for her to handle. Riko notes that her shy personality better suits his personality as Keita is not too comfortable with public displays of affection. Riko is known to openly express her jealousy whenever Keita gives another girl attention, even starting a one-sided fight with him.
Miharu - Ako views Miharu as a rival for Keita's affections and shows jealousy of her big bust.
- Riko's bandage covers up a scar she received from when Keita threw a toy at her during their childhood.
- Riko will not let anyone see the scar under the band-aid as it is a promise to her that Keita will marry her. When Yūzuki removed the old band-aid during their beach trip she instantly dashing to a store, buying and applying a new one before anyone could see it.