Butei Charter Article 1
Kinji works quickly and uses a medicine to save Aria's life. When Aria yells at him as a result, Kinji kisses her to simultaneously calm her down and activate his Hysteria mode. Confronting Riko as she approaches. Just then the plane starts descending, so Aria rushes to the controls whilst Kinji confronts Riko, who escapes after blowing out the plane's door before the plane is hit by missiles, blowing out some of its engines and causing a fuel leak. Despite interference by the government, Kinji manages to ease the plane into an emergency landing thanks to the other Butei. Afterwards, just as Aria is prepared to leave, Kinji agrees to be her partner, though this does not settle well with Shirayuki.
Aired 13/05/2011EP 5 - Butei Charter Article 1

Aria the Scarlet Ammo
Aria is a volatile girl who’s top dog in assault at a school for young mercenaries. When she discovers her classmate Kinji’s an ace, she strong-arms him into being her partner, but she isn’t the only femme fatale who wants a taste of his combat skills. His secret? He’s only a hotshot when he’s turned on! Aria gets Kinji for one mission, but he’ll end up with more than one finger on his trigger!
(Source: Crunchyroll)