Prequel to .

A squid-like creature, known as a Happian, leaves his home planet with the desire to spread happiness across the universe. He lands on Earth, but quickly finds himself in danger of captivity by its inhabitants. Fortunately, he is found by an unsmiling little girl named Shizuka Kuze, who feeds him and names him Takopii. Feeling indebted, Takopii decides to do everything in his power to bring a smile to her face. The task is easier said than done, however. Shizuka is bullied by her classmates, she does not have a father, and her mother is never home—though the gravity of these issues flies over the naive Takopii's head. Even so, Shizuka does have one source of happiness: her dog Chappy. The connection Shizuka and Chappy share only increases Takopii's desire to make the girl smile. While Takopii's attempts to lift Shizuka's spirits lead to unintended consequences, he is determined to take things into his own tentacles, test his understanding of human beings, and achieve his goal of spreading happiness.

After Marin Kitagawa introduced Wakana Gojou to the world of cosplay, he has been creating her outfits with ease. Even so, he still has a lot to learn, and every new lesson seems to strengthen his love for sewing and for the hina dolls his grandfather taught him to make. Meanwhile, Kitagawa finds it harder and harder to hide her feelings for Gojou. Friends and strangers alike constantly mistake them for a couple, much to Gojou's embarrassment. After all, in his eyes, their worlds are far too different for anyone to think they could be romantically linked. However, as Gojou spends more time with Kitagawa and realizes that his passions are not ridiculed by other people, a relationship between the two no longer seems so far-fetched.

While the mission to exorcise Jin "Jiji" Enjouji's family home is underway, things are not going as expected. Momo Ayase narrowly evades an attempted abduction while Ken "Okarun" Takakura and Jiji are ambushed by the Kitou family—the unsettling landlords of the cursed estate. The trio's efforts threaten the foundation of this enigmatic town shrouded in legends and mysteries. As Momo, Okarun, and Jiji are drawn deeper into the maze of folklore and supernatural entities, they must each utilize their unique powers if they want to survive and unravel the secrets of the uncanny town.