Aoi Satsuki is the male representative for May and an idol with Tsukino Talent Production, part of the unit Six Gravity. He has platinum-blonde hair with a faint tawny shade, featuring two distinctive outward-bending tufts resembling wings, and sky-blue eyes. His height slightly exceeds the average for males his age, though his growth appears to be stabilizing. He is frequently described as exceptionally handsome, a trait shared with his family, well-known in their neighborhood for their good looks. He particularly resembles his father and older brother, Chihiro. A notable characteristic is the momentary flash of light that accompanies his smiles.

Aoi exhibits a refreshingly level-headed and adult-like personality, often assisting Yayoi Haru in supporting and managing the other members of Six Gravity. Diligent and serious by nature, he finds it challenging to relax or engage in leisurely activities and struggles with romantic narratives. Despite his mature demeanor, he harbors a more childish side, initially reserved for his childhood friend Uduki Arata but gradually revealed to the broader group over time. He occasionally experiences feelings of loneliness.

His history traces back to the Satsuki family, where he is the youngest son. He and Arata were scouted during an attempt to return a lost pet, Kuroda, using the contact information on the animal's collar. Aoi debuted as an idol in his second year of senior high school.

Aoi's relationship with Arata is particularly significant. The two have been friends since kindergarten through shared schools, and their families frequently vacation together. Aoi consistently looks after Arata, tempering his friend's easygoing attitude, while Arata helps Aoi unwind. Conflicts between them are rare, occurring approximately once every six months. Professionally, their first solo job together involved recording a special edition of TSUKIRadi.

During the events of the second season, Aoi collaborates with Arata to produce an "adventure"-themed fan event. Perceiving adventurousness as a personal shortcoming, Aoi dedicates considerable effort to designing a puzzle/escape room experience at a zoo, aiming to provide attendees with a sense of the extraordinary. This undertaking highlights his meticulous and caring approach.

Aoi also experiences seasickness, a trait he shares with Kisaragi Koi, Minaduki Rui, and Nagatsuki Yoru.