A young man visits the island where his late grandmother stayed, and gets involved with pretty girls living on the island.

Author Hotaru Yuyami has just tragically lost his beloved dog. While gazing at a tree in his yard, he notices a strange pink mushroom, and it's...moving?. The mushroom suddenly turns into an adorable dog, and Hotaru decides to take it in. Now, alongside his editor and a mushroom researcher, Hotaru shares heartwarming and hilarious moments with his new capricious companion.

A group of girls hop onto an abandoned train to explore the outside world with strange anomalies.