After an unending battle between the cat and the mouse, peace reigns supreme. This tranquility is interrupted by the unexpected arrival of Na-tan, an Eto-musume (Zodiac girl), leaving the 12 signs baffled and Nya-tan ecstatic due to her pure and straightforward nature. However, this joyous atmosphere is short-lived as Chu-tan warns of an impending catastrophe: "The seal...has been broken." The identity of the enigmatic Na-tan remains a mystery as the deity that awakens below the seal remains unknown.