Kanie Seiya, a smart and extremely narcissistic high school student, believes that the beautiful but reserved Sento Isuzu has invited him on a date at an amusement park called Amagi Brilliant Park. Much to his chagrin, not only is the location a run-down facility, the supposed date is merely a recruitment tour where Sento and Princess Latifa Fleuranza, the owner of the theme park, ask him to become the park's new manager. Their cause for desperation? As stipulated in a land-use contract, Amagi has less than three months to meet a quota of 500,000 guests, or the park will be closed for good and the land redeveloped by a greedy real-estate company.

Chise Hatori, a 15-year-old Japanese girl, was sold for five million pounds at an auction to a tall masked gentleman. Abandoned at a young age and ridiculed by her peers for her unconventional behavior, she was ready to give herself to any buyer if it meant having a place to go home to. In chains and on her way to an unknown fate, she hears whispers from robed men along her path, gossiping and complaining that such a buyer got his hands on a rare "Sleigh Beggy."