Puniru is a Kawaii Slime

Puniru follows Kotaro to school to take him something he forgot, but they end up getting into a fight. Puniru turns into an idol to get Kotaro to admit she's cute. Kotaro tries to enlist Puniru's help in winning the affections of his crush, Kirara-senpai.

Puniru gets moldy and down in the dumps when Runrune starts ignoring her. Later, she's determined to get Runrune and Alice to be friends again. Next, AI Runrune hits the scene, and Alice and Puniru face off to see which Runrune is better.

Kotaro and the boys go to the beach for a day of fun while Puniru and Kirara-senpai are at the school pool. Later, Kotaro asks Puniru to help him cool off with a special transformation, the gang hits a café, and then it's time to tackle summer homework.

It's time for the school festival, but Puniru and Alice get into a fight over Kotaro. Alice tries to win him over with an incredible offer, and Puniru tries to throw the match so he can pursue his dreams.

Kotaro wants to be cool and decides to try his luck with dragons and a rock band. Puniru then lets the cat out of the bag about Kotaro's feelings for Kirara, which forces him to make a move. Can he get Puniru to help him out?

Ever since being teased as kid for liking cute things, Kotaro has never enjoyed Christmas. This year his parents are going on a trip for the holiday, so in order to avoid being stuck home alone with Puniru, he tries to throw a Christmas party.

Puniru says she'll spend the holiday with whoever brings her the cutest Christmas cake, but the offerings she gets are... interesting. When a certain someone loses their patience, she may yet get a Christmas to remember.

Out of the blue, Kotaro wins tickets to a ski resort—specifically the Runrune Resort run by Alice. When they get there, Puniru is determined to make an impression, and her desire to be cuter than ever may just spur even greater adventure.