Touko is a senpai one year older to Konoha and the president of the literature club. She likes literature to the extent that she eats what she reads. When Konoha saw her eating the pages of a novel, she forced him to join the literature club so that she could "watch over him" and keep him from telling others about it.

Spoiler

She also likes Konoha, but chose to leave him. Her past was revealed in the "Romancie" books. Her father was the editor of Miu Inoue's only book. This is why Touko knew what the original ending of the book was, and also that Miu Inoue was actually Konoha. Being his first fan, she's been waiting for Konoha to write another book. Her parents died in a car accident. Her mother used to write "snacks" for her, but after their death, she could find no one else to write them before meeting Konoha.