Ai is Sai's (X) accomplice in crime. She primarily handles the cleanup at crime scenes. Additionally, she ensures that Sai maintains his Phantom Thief X persona by urging him to take something from each place he commits a murder. Although this task irritates X, he typically grabs the nearest item to hand over to Ai. Consequently, Ai has mentioned that her house is cluttered with B-grade goods.
Prior to meeting Sai, Ai was known as Plane Crasher Imina, notorious for bombing planes mid-flight. Despite her notoriety, the authorities were unable to apprehend her due to her elusive nature. During her tenure as Imina, she worked for a larger organization and continued her activities while feeling constrained by human limitations. She desired to live life without being bound by these constraints. Her first encounter with X occurred during a flight to San Francisco. Though initially surprised, she quickly became drawn to his character. After disembarking, she discovered that her superiors had planned to betray her, intending to offer her to the government as a gesture to start anew. She left X to deal with the men and subsequently joined forces with him.
Depending on the day, she refers to Sai as Master, child, friend, lover, brother, sister, or other terms.
Source: Wikipedia, Neuro Wiki
