八木沢

Affiliation: The Association
Bug: Centipede
Ability: Parasitism - Living Behind. A dangerous bug that gives its host great powers at the cost of destroying their body and mind.

Newest and youngest member of the Association trio who likewise shares the other two's interest in bug history and research. The terrifying price of her Centipede and the difficulties in controlling it forces Yagisawa to be hospitalized most of the time, with Watanuki being her primary caretaker. She has also developed a friendship with Hitotsuya, and the usually introvert latter views Yagisawa with affection.