After saving Mouselette from her terror, Kouchu and his friends have to return to Justpip Town when they are suppose to be at Dark City for the Medal. The brawlers headed to Justpip Town so that they could help Dustin with Professor Shari's lab. However, Shari let Dustin in charge of her lab, while she runs a big errand on buying a special potion, so with Kouchu and his friend's help, Dustin offers to impress Shari of what a good house sitter he is by cleaning the mess, and getting rid of big rats, Dustin have made effort to take care of Shari's laboratory, so does the help of the Crystal Brawlers.
