Crayon Shin-chan Spin-off

A strange monster-related incident occurs in a rural town! A monster born from the grudge of unwanted hair attacks Fumie Sakura, a girl who lives there. Then a monster boy, O-O-O-No Shinnosuke, and his father, Daddy Little Balls, come to the rescue. They are looking for the family's mother. This was the beginning of the epic case of the monster-related problems that would ravage the town.

Fumie takes the monster father and son back home with her. Shinnosuke senses a strong monster vibe and they head to the source. They discover that the monster is not Shinnosuke's mother but a cleaning monster that uses extreme measures to declutter. Fumie, Shinnosuke and his father are tasked with getting rid of the monster at the desperate family's request.

Fumie convinces Shinnosuke and his father to form Monster Busters with her to tackle the monster-related problems cropping up around town. She tries to advertise the service to her friends at school but everyone is more interested in lunch, which happens to be curry that day. But a monster that makes everything super spicy appears and makes their curry inedible. It's a job for Monster Busters!

Monster Busters is hired to take care of a monster infestation at a normally tranquil hot spring inn in the mountain. They arrive to find that the cause of the commotion isn't monsters but a bunch of partying people, to Fumie's chagrin. But a monster flower emerges from inside the hot spring, and its pollen turns Shinnosuke and his father into party monsters.

One day, Fumie sees a single tattered monster glove walking soaking wet in the rain. She presumes that it has lost its owner and feels sorry for it. She takes it home, names it Chocolat, and tries to attend to its needs. It turns out, however, that the monster glove has other, surprising plans that evening.

Fumie hears about a camping site where people are going missing, and heads over with Shinnosuke and his dad to investigate. They follow voices coming from deep in the forest and discover a group of people who have been turned into mushrooms by the "Evil Mushroom King". The evil monster catches the Monster Busters by surprise, and they are all turned into mushrooms and truffles.