Negima!? Magister Negi Magi Episode 16: Yesterday`s Foe Is Today`s Friend. Good Enough Friends to Have Fights. No Doesn`t Always Mean No.
Episode 16 of 26 of Negima!? Magister Negi Magi, aired January 17, 2007, 25 minutes. Available with English subtitles and dub where released.
Episode summary
An argument between Asuna and Ayaka results in competition in a series of challenges. However, when a Dark Seed magic appears, Ayaka recalls her friendship with Asuna and uses her Armor form to rescue her.