The story centers around high school student Seiya Kanie, a self proclaimed genius with looks, intellect, and athletic ability. On a Sunday, a mysterious transfer student who carries a musket gun takes him to an old and deserted amusement park, Amagi Brilliant Park. He is told that if the park can't attract 100,000 visitors in the next two weeks, it will be closed immediately. And thus the business comedy, Amagi Brilliant Park, begins!

Wikia - https://amaburi.fandom.com/