Kabutomushi is a small friend of Chiikawa.

One day, in the depths of a certain cave, Chiikawa found this mysterious creature. It was in a cave with iron bars, as if imprisoned, and when Chiikawa and friends accidentally opened the switch of the bars, Kabutomushi came out.

After that, it followed Chiikawa, who had let it out of the cave, and Chiikawa, who had grown fond of it, took care of it. Yoroi-San initially felt apprehensive as it was an unknown creature, but eventually accepted it due to its small, harmless, and adorable nature.

But what happened next......?