Ability: I Am a Cat; allows him to turn into a calico cat. It is commonly said that Natsume is the strongest ability user, able to see through all kinds of things. Until the end of the Cannibalism events, his ability remains unknown to anyone; only then he reveals the nature of his power to Fukuzawa, Mori, and Katai by turning back into his human form.

Natsume Souseki is a writer and former mentor of Yukichi Fukuzawa and Ougai Mori.