|Age|| 16 |
17 (as of Chapter 75)
|Eye Color||Raw Umber|
|Relatives|| Mr. Suminoe (step-father)|
Mrs. Suminoe (mother)
Riko Suminoe (sister)
Keita Suminoe (step-brother)
Student Council General Manager
|Manga Debut||Vol. 1, Ch. 0|
|Anime Debut||Ep 1, OVA 0|
|Voiced By||Anyana Taketatsu|
Ako Suminoe (住之江 あこ, Suminoe Ako) is a 17 year old, second-year high school student. She is the elder of the twins and the eldest step-sister to Keita. Like Keita, she is one of the main characters of the series.
Ako has tuscan red hair worn in a shoulder length wide ponytail, with a hair clip to keep her hair off her forehead and a wide forelock to the right side of her face. Her eyes are raw umber, like those of her sister Riko.
Ako is very bright and cheery. Eldest among the twins and the siblings, Ako is more accomplished. She is intelligent, responsible and maternal. She excels in her studies and housework. She also endeavour to maintain a prim and proper demeanour. Despite this, Ako can be emotional, childish, peppy, easily embarrassed, whiny, reluctant and perverse, especially her well-known open secret.
Ako is also the general manager of the student council for her school. However, like Riko, she abuses her authority to get some alone time with Keita. Besides being unafraid of abusing her own authority, Ako is also unafraid of covering up an embarrassing occurrence, such as when she asked Keita to pick up her, Riko's, Miharu's, and Kiryu's alternate clothes when the teacher and the twins (Miharu was in a stall that was hit with a wild shot) got into a severe water fight in the girls' bathroom over the twins' romantic interest in Keita.
Ako also has a habit of giving names to kisses in certain occasions, such as the “welcome home kiss,” the “make-up kiss,” the “study well kiss” and so on, much to Keita's annoyance.
Riko - Her twin sister and rival for their step-brother's affections. Disapproves of Riko's more openly lewd nature, 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 "Kei-chan" to her, Ako loves her brother deeply. Though she normally has a mature personality, being with Keita brings out her childishness. While she may not be as manipulative as her sister she knows full well how to get Keita to do what she wants. She becomes very self-conscious whenever Keita decides to engage in any sexual activity with her, not wanting any visible marks on her body where it can be seen in public such as her neck; Keita however finds her shy expressions cute.
Miharu - Riko views Miharu as a rival for Keita's affections and shows jealousy of her big bust.
- It was seen in the anime that Ako offered to be Keita's tutor during his short test in order to improve his passing rate. When Keita couldn't remember about anything except for her private parts, Ako uses another method of teaching Keita: writing the notes all over her body.
- While having a special tuition lesson with Keita, Keita accidentally pushed away part of her underwear which covered the word "at last".