Lapis and Ruby, the henchmen of General Zircon, carry out several attacks on the innocents of Budapest in an attempt to steal what is known as 'The Star Jewel' as a means of powering their ship, 'The Solaris'. The jewels are a source of power originating from the human heart and are also the life source of that being, so in removing the jewels from their owners would result in the beings remaining in a comatose state or presumably death. Kanna Reiko, Jinno Natsumi and Kamisaka Mei, known as 'The Drivers' are the guardians of the region and are dispatched to deal with the interlopers while returning the jewels to their rightful owners through any means necessary.