Puniru is a Kawaii Slime: Season 1, Episode 7

1 - 7: Sweet Bitter Summer

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.