Futaba Igarashi

Gender: Female
Age: 23
Height: 130 cm (4'2")
Weight: 27 kg (60 lb)
Blood type: A
Date of birth: March 9
Eye color: Forest Green
Place of birth: Hokkaido

Igarashi Futaba is the female main character in the series. She is 23 years old and often gets mistaken for a high-school girl due to her height.

She has a crush on her senpai, Takeda, but is too shy to admit it.
(Source: Senpai ga Urusai Kouhai no Hanashi Wiki)