Itsuki Nakano

The fifth daughter of the five sisters. She is characterized by her slightly quirky long hair, an ahoge sprouting from the top of her head, and star-patterned hairpins. Her image color is red. She calls Fuutarou "Uesugi-kun." Among the quintuplets, she is good at science.

She is serious but not very efficient, and although she is motivated to study, she struggles to succeed. She consistently uses polite language with everyone. She is quite a foodie, and there are many scenes of her eating in the story. She is very scared of ghosts and horror movies. Among the five sisters, she was the most attached to their deceased mother and never misses visiting her grave on the 14th, which is the monthly anniversary of her mother's death.

Despite knowing about Fuutarou's family situation, she sometimes asks for seconds at his house or, in her excitement when Fuutarou decides to resolve the sisters' troubles, she barges into a mixed bath with just a towel, showing a slightly absent-minded side. She is the first sister to meet Fuutarou in high school and becomes his classmate. Initially, she asked him to teach her, but after being refused and receiving an insensitive comment, their relationship started off poorly and remained strained. However, she gradually began to open up to him, and their arguments became less frequent. Later, she dreams of becoming a teacher like her mother. Due to their biological father, Mudou, abandoning Rena and the quintuplets, she has a somewhat fastidious attitude towards men.

In the confectionery industry, she is also known as the reviewer "M.A.Y." After advancing to the third year, she starts a part-time job assisting a cram school teacher.