Although it was first released five years before Sonic Wings, the horizontally-scrolling shmup Rabio Lepus set the stage for the Sonic Wings series with its style of gameplay in addition to its cast of characters and bizarre enemies. In Rabio Lepus, the princess of Bunnyland, Komomo Kitashirakawa, has been kidnapped along with her sister Kotomi Kitashirakawa and their grandfather the king, Taro Kitashirakawa. The mechanical rabbits Rabio and Lepus rescue the royal family by fighting enemies on a spaceship, an asteroid, and the enemy's planet.