The story opens with Kyohei Tachibana, a student at a culinary arts school with dreams of someday becoming a patissier, motorcycling down an inner city street and becoming caught up in a shoot-out between a mysterious white-haired woman and a couple of gangsters. Kyohei escapes unharmed and ends up working as a cook for a group of four girls named Jo, Meg, Amy, and Sei in an effort to gather up enough money to travel to France. The girls, ranging in ages of eleven to nineteen, turn out to be pseudo-mercenary agents for a larger international group known as Bai Lan. The anime focuses on the group as they investigate a series of mutated human monsters with odd glowing brains that cause various amount of mayhem mostly throughout the Tokyo, Japan, area. There are also a couple of side characters (namely the group's mecha, Jango, that is maintained by a man named Leo) along with various third persons that occur throughout or in specific parts of the series, such as a new Japanese Prime Minister that takes over via an assassination of an early, newly-elected Prime Minister nearing the end of the series