Wealthy heiress Catarina Claes is hit in the head with a rock and recovers the memories of her past life. It turns out the world she lives in is the world of the game Fortune Lover, an otome game she was obsessed with in her past life... but she's been cast as the villain character who tries to foil the protagonist's romances!

Endo and Kobayashi love to bicker about their latest video game fixation. They think they're simply providing color commentary, but one of the game's characters, Siegwald, can hear them talking about his fiancée, the villainess Lieselotte!

In a world consisting of numerous isles, a young hero from the Astora Isle encounters the adventurer Kyle and follows him on an expedition on the isle. They meet a mysterious girl named Iris and a talking white cat, and together they make their way to the isle's ruins, where they find a flying island. Kyle becomes consumed by darkness there, and the party resolves to travel to the ends of the world on the flying island in order to find the seven "Great Runes", following Kyle's words before he disappeared.