Aoi is a girl with long blue hair, blue eyes and a fair complexion.
Befitting her lady-like image, Aoi is soft-spoken and acts with grace. For some reason, she hates tomatoes, and ironically, this allowed her to create a close bond with her best friend Akane.
Aoi is the second known user of the Vivid System, right after Akane activates the system for the first time. Her Palette Suit, which bears a close resemblance to Akane's, has a blue color scheme instead of Akane's red and uses a hammer as her primary weapon.
- Superhuman Strength - Aoi is capable of slowing down a flying fighter jet to a complete stop and has more than enough strength to carry a fighter plane from its nose. The fact that she can wield the Naked Impact, which is a heavy weapon in itself, also tells about Aoi's immense strength.
- Weapon: Naked Impact - Aoi's personal weapon in the form of a two-headed hammer with a slender handle. It is known to be very heavy, and has the ability to deflect incoming attacks by simply using the weapon as a shield or by hitting incoming projectiles by using it like a hammer.
- Docking Operation - Allows Aoi to combine consciousnesses with other users of the Vivid System, activated by a kiss on the forehead.
- Docking Operation: Vivid Blue Operation - When the conditions are met, Aoi can merge with Akane, combining their consciousnesses into one physical body, with changes to their outfits and weapon dependent on which is the receiver or the giver of the kiss. During their first Docking as Vivid Blue Operation, Aoi kissed Akane, causing Akane to take over their temporary body while Aoi governs the color scheme of the Palette Suit and weapon used.
- Upgraded Weapon: Vivid Impact - A much larger version of Naked Impact, with upgraded versions of the basic properties of the Naked Impact. It also has the ability to gather power by releasing the safety protocols implemented into the weapon.
- Final Operation - Upon gathering the desired amount of energy, Akane and Aoi can release this into a powerful hammer strike, which has enough power to defeat an empowered Alone in one strike.
- Her full name literally translates to "two blue (flower) buds".