A shapeshifting slime girl with endless energy is your best friend, and she will exhaust you with pure joy. Kotarou can't win, she doesn't let him, and that's the entire joke, executed with timing sharp enough to land in your chest. The animation stays vibrant and loose, never taking itself seriously, because a show about a boy and his impossibly cute slime doesn't need to.

Back in elementary school, Kotarou made a slime that unexpectedly came to life. Seven years later, he is a second-year middle schooler, and Puniru, still his closest friend, has grown into a beautiful, carefree girl who can reshape herself into all sorts of cute forms. Her free-spirited transformations and wild antics leave him flustered and thrilled in equal measure, and he never gets a moment's rest. Mixing comedy, fantasy, romance and slice of life, the story asks whether the two can go on being just friends as they keep growing up.