Sumireko Ogawa

Aspiring novelist and bookstore clerk. One day, while at work at the bookstore, she picks up a book that was shoplifted in reverse, leading her to become involved with various supernatural occurrences alongside her colleague, Ren Adashino. At the age of 15, she won a newcomer's award and had her novel published, making her debut after writing it in the literary club, but as an author, she has been smoldering for over 10 years since then. She is 28 years old. Her measurements are 100-62-93. After reading a cursed book, she becomes a Wochibito, a person who can rejuvenate at will.

The creator, Nujima, initially imagined Sumire based on the character Sumire from Haruki Murakami's "Sputnik Sweetheart," and as a background setting, her favorite author is stated to be Fumi Umi.