Momoka Nanase
One of the protagonist’s younger sisters. She’s unaware of just how much she spoils her brother. With their parents gone on vacation, she’s taken up all the housework herself.
Her talent for cooking is fairly remarkable, particularly her specialty in baking sweets.
Momoka is devoted to her beloved family, and has a kind, often motherly personality.
While she may look like she has everything together, she can’t keep that facade up at all times, especially when it comes to her weakness for sugary foods, leaving her constantly self-conscious about her waistline.
She tries to restrain herself for the sake of the other sisters, but, like them, she’s been in love with her brother from a young age.
Ririna Nanase
One of the protagonist’s younger sisters. She’s loudmouthed, but also caring.
A studious girl, Ririna takes charge both at school and in the home, acting to organize the rest of the siblings. Germophobic and hateful toward men, she’s frequently harsh on her slovenly and perverted elder brother.
Her typical reaction to hearing a dirty joke is to deliver a swift kick to its teller. Despite all her complaints, she can’t bring herself to hate her brother, and deep down, she truly loves him.
As Ririna cannot outwardly condone sexual behavior, she must make absolutely sure nobody ever finds out about her masturbation habit.
Yuzu Nanase
One of the protagonist’s younger sisters. She somehow finds a way to trip over absolutely nothing. Her continually clumsy and hectic nature, coupled with her young appearance and amusingly over-the-top reactions, lends her something of the appearance of a lovable mascot character.
Yuzu has a complex about her short stature and minuscule chest, and so wants to become a mature adult as soon as possible. She often clashes with her teasing elder brother, but still loves him at the end of the day.
Although Yuzu knows little about sex, as she doesn’t want to be treated like a child, she pretends as though she’s an expert on the subject.
Chiharu Nanase
One of the protagonist’s younger sisters. She always smiles when they’re together.
A lover of anime, manga, and video games, she’s abnormally close with her brother and plays with him constantly. Her high level of energy rubs off on the rest of the Nanase family.
Chiharu is inclined toward exercise, and is a member of the cheerleading squad.
She eats a lot, plays a lot, and sleeps a lot, but hates to study. Unlike most of the other sisters, she doesn’t even try to hide her love for her brother.
Whenever she sees the chance, she charges right at him with a powerful tackle. She’s happy to talk about sex, and even tells dirty jokes like they’re nothing.
Chiharu is also not shy about trying to seduce her brother, no matter the time or place.
Shizuku Nanase
One of the protagonist’s younger sisters. Her two favorite things are her brother and reading.
The sight of her silently reading a book is beautiful enough to be compared to a painting, but the moment she opens her mouth and says something bizarre, that image is ruined.
Both unpredictable and prone to believing whatever she reads, the knowledge she picks up from one strange book or another always leads to trouble for her family.
The ways in she expresses her love for her brother tend to be rather unique, but her affection is so earnest that she really will do anything for him. As the combined result of knowledge, training, and her natural talent, Shizuku’s sexual techniques end up surpassing all expectations.
