Prior to becoming Aria's Amica, Akari worshiped her and aspired to be like her. She even went as far as risking her life by pushing Aria out of the way of a moving car. After becoming her Amica, she proved to be extremely loyal and eager to learn under her. On one occasion she hand stitched a parachute for her and even completed it in record time because she was doing for Aria.
A close friend part of the circle Akari and Shino are in. They have a playful relationship, demonstrated when Raika flips Akari's skirt upwards to put her gun back into its holster. Akari has helped Raika and Kirin's relationship progress. Though not as protective as Shino, Raika has proven her loyal friendship through helping Akari save her little sister in mission "AA", a life-risking task.
They met a while back while Akari was getting leaf pies. There was only one pie left, and Shino allowed Akari to have the last. Akari shared the pie with Shino, taking the title of Shino's first friend. Because of Akari's friendly demeanor and being the first friend of Shino's, the latter is obsessive with Akari. She's spiteful of Aria because of Akari's admiration for her, and collects pictures of Akari. She's also very possessive of Akari and would do anything for her.
Initially, Akari was very suspicious of Kinji due to the fact he was the only person at Butei High that Aria actively took interest in and sought out. However, she also fears and respects him to some degree due to how in his freshman year he had defeated an instructor during the entrance exams and achieved an S-Rank in Assault. Though their interactions are few and far between, Akari gets defensive of Aria whenever he appears. However, she has shown to work with Kinji when comes to Aria going berserk as shown in Volume 12.
On a practical exam, Urara had looked down and taunted Akari for being so weak. However, later during the quartet battle where Akari's team was against Urara's, Akari outsmarted and beat Urara. In the anime, Kyou would sabotage the surrounding work complex causing it to collapse on them. Despite Urara's rudeness to Akari prior the test, Akari stayed behind to help save Urara. After that event, Urara grew an obsession similar to that of Shino's with Akari. She is willing to do many things for Akari and has perverted fantasies of dominating Akari.
Akari worked with Kaname during Volume 11 in a plot to keep Kinji and Aria separated from each other.
Nonoka is Akari younger sister who she loves very much and goes out of her way to defeat Kyouchikytou and retrieve an antidote to the poison Nonoka was infected with during the Mamiya Family massacre.