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.

As novelist Fuji is returning home in a rainstorm, her attention is caught by something peculiar: an animal resembling a dog asking her to take it in. Although she is reluctant at first, the animal impresses her by handing her an umbrella, resulting in Fuji welcoming the creature into her apartment. Soon, Fuji realizes that the animal is even smarter than she initially thought, as it begins communicating with her through writing. Whether the two are alone or hanging out with her family and friends, Fuji's new little friend never fails to entertain with its whimsical actions.

Due to frequent misadventures with the supernatural and her hectic school life, Nene Yashiro can barely catch a break until Kamome Academy's annual sleepover event comes around. Nene is excited to blow off some steam with her best friend Aoi Akane and the rest of her class at the get-together. Unbeknownst to her, the sleepover falls on the same date as Urabon, when the line between the dead and the living gets distorted, allowing wicked spirits to come out to the surface. When an evil ghost is about to attack her, Nene is rescued by a mysterious figure: Shinigami, the Sixth Wonder that can trap souls using his flute. In that moment, Shinigami takes notice of Aoi and abducts her to use her as a sacrifice that will close the barrier for good. Joined by Hanako-kun and Akane Aoi, Nene must embark on a journey into the deepest confines of the world of the dead to save her best friend before it is too late.

This is the story of Puniru the slime and Kotarou, a middle school student, until they cease being friends... Kotarou Kawaii is a second-year middle school boy. When he was in elementary school, a slime he created came to life, and for the past seven years, he has been spending time with the slime named Puniru as his "friend." However, there is one problem for Kotarou... Over the seven years, both have grown significantly, and Puniru has transformed into an incredibly beautiful girl! Besides her beautiful appearance, Puniru freely transforms into various cute forms as a slime, causing Kotarou to be both excited and bewildered by her carefree behavior every time. Will Puniru and Kotarou be able to continue spending time together as "friends" despite these challenging days ahead?