Michiko's childhood friend and rival. Atsuko, a police officer, was responsible for arresting Michiko 12 years before the main plot. Though she outwardly rues having to chase Michiko down after her jail break, there is a part of Atsuko that takes great pleasure in the whole affair.

Michiko frequently calls her "Jambo" (a Portuguese word for some syzygium fruit that can also refer to a dark or brown-skinned person).