A talkative girl who can't stop talking about physics and mechanisms of machinery. Whenever there is a mechanical problem at Millennium, she is the first to arrive on the scene to explain the situation.

Nicknamed as the Walking Encyclopedia. Whenever there's a problem or if someone asks a question, She would go as far back as its history and explain every single detail. Due to this, people often tend to avoid talking to her, just so they don't have to hear her lectures.

Member of the Engineering Department.

A cheerful schoolgirl from Trinity General School and a member of After-School Sweets Club.

She has an easygoing personality and loves to spend time chatting with her friends while eating sweets more than anything else. Her favorite food is ice cream and has recently developed a taste for chocolate mint flavored.

Member of the After-School Sweets Club.

A member of the After-School Sweets Club at Trinity General School. She has a complex about her height and physique, and always gives the impression of an angry small animal.

Despite wanting to look mature, she is always doted on for how her thoughts are reflected unchanged in her facial expression. Yoshimi's pastime is visiting cafes, tasting limited edition sweets and occasionally— smiles brighter than anyone else.

Head of the After-School Sweets Club.

A mathematical genius from Millennium Science School, she's is a troublemaker, a gremlin, member of the "Seminar" student council. She causes problems to the members of "Seminar", especially Yuuka and Noa.She normally uses internet slang.

She is a prodigy when it comes to analyzing probabilities, although she herself completely unaware of it. Likes games of chance, and constantly tries her luck in various ways. Even when she is in trouble, she never gives up.

Cryptanalyst and member of Seminar

President of the Filius faction.Refined and soft-spoken, but rarely reveals her true feelings, making her complicated and mysterious . Her hobby is collecting and preparing tea leaves and sweets for tea parties and tending gardens.
She is quite calm and composed, but like everyone else, she has her limit, and she can get quite ruthless once someone breaks her composure. She also tends to overthink things 

She dreams of a day when many Trinity students would be invited to a tea party of hers.

The Refined head of the Tea Party

The president of the Festival Management Committee at Hyakkiyako, owner and poster girl of the coffee shop of the classic-japanese style cafe, Momoyodou.

Despite being a little clumsy, she's a professional who do whatever it takes to see the success of her efforts for the festival and Momoyodou. She's a bit ambitious with money.

Beneath the surface shows cracks in her personality as she can get vindictive and aggressive when provoked, but she usually has a relaxed personality. She's a bit