Chapters 26-34 of the manga comprise the Hoshi no Umi arc, which has been adapted into an OVA format. The arc revolves around Rin Azuma, a Jiang-Shi yokai residing in Sakurashin and working in a ramen shop while adjusting to city life. Zakuro Kurumaki, Rin's former friend, invades the city along with the main antagonist of the series, Enjin Hiizumi, with the aim of convincing Rin to join them in destroying it. The Hiizumi Life Counseling Office, led by Akina Hiizumi and his colleagues, must take action to rescue Rin, suppress Zakuro's control over yokai, and safeguard the city.