Natsume goes to a hot spring for a school trip, with an errand from Shigeru to pick up teacups from a near by pottery. While there he meets and helps a little fox spirit, who quickly grows attached to him.

Natori invites Natsume on a hot spring trip. But noises from the closet and a kimono-clad figure dangled from the ceiling make Natsume uneasy. Not wanting to trouble Natori because of his kind gesture to enjoy the hot spring with him, Natsume investigates the hot spring himself. During the night, Natsume meets with the Youkai, where she comments that he is too soft, and attacks.

(Source: Wikipedia)

Natsume takes care of an abandoned egg from a nest, not considering it could be a Youkai. After it hatches, it turns out it is a rare baby spirit called Tatsumi, who thinks that Natsume is its parent. Natsume can't help but get attached to the little spirit even as Tatsumi grows tired and sick. But as Natsume takes care of Tatsumi, a mysterious spirit comes and wants to take away Tatsumi for his master-who wants to eat him.

(Source: Wikipedia)