Natsume Yuujinchou: Ishi Okoshi to Ayashiki Raihousha

A young boy named Natsume encounters a small spirit named Mitsumi in the woods, who is tasked with awakening the ancient spirit Iwatetsu from a long sleep. Concerned for Mitsumi, Natsume decides to assist in this endeavor. Separately, a mysterious figure begins visiting Tanuma regularly, engaging in brief conversations before departing. Though the figure is identified as a spirit, it does not appear hostile. Despite this, Tanuma's health gradually declines as the visits continue.