Aria the Scarlet Ammo - Season 1 Episode 10 -

Riko explains the plan of how they will infiltrate the mansion and claims that they will go in undercover as a butler and maid. With the agreement done, they undergo one more ‘training session’ where as Riko helps train Aria to say some lines and get time stuck in her head, and aims to practice triggering Kinji’s Hysteria Mode. At the same time, Kinji learns a bit about Riko’s past thanks to Jeanne who is now a student at the school.