Nago

Nago is one of the female characters in Daily Lives of High School Boys.

Background
She is a high school student of Central High School. She works part-time at Pizza-Le with Tadakuni and Yasunori. She is a fastidious worker who gets annoyed with her male co-workers’ narcissism but doesn’t fail to humor them once in a while. She acts as a confidante to Tadakuni and gives him advice. She wears eyeglasses, had wrinkles on her face, and is rather plump. At work she wears her red kerchief and removes it when she's going home from work.

Highschool Girls Are Funky
Later in the series, a different Nago appeared; this Nago is depicted to be slimmer and does not have wrinkles, different characters are used in her name, and she is not referred to with the honorific “-san.” She still has her eyeglasses and, queerly, wears the red kerchief from the pizzeria, which the first Nago removes outside work. Going to the same school, Yanagi considers her as a rival in academics and skills and challenges her frequently. Despite not knowing who Yanagi is, Nago humors her challenger and surpasses her in every aspect.

Epilogue - "High School Boys and Extras"
While the relationship between the two Nago’s is up for debate, a scene in an extra chapter of the manga’s final volume depicting the second Nago with Tadakuni at the Culture Festival implies that they are one and the same.