Shinobu and Lum from Urusei Yatsura.
Sakura and Aoi from Dangan Ronpa.
Anthy and Utena from Revolutionary Girl Utena.
Snow Miku and Cherry-Blossom Miku from Vocaloid.
Setsuna and Asuna from Negima.
Diana and Anne from Akage No An.
Mikasa and Annie from AoT.
Madoka and Homura from PMMM.
Bubbles and Bubbles from PPG and PPG Z.
Ranma and Shampoo from Ranma 1/2.
Cure Dream and Dark Dream from Yes Precure 5.
Yurisha and Yuki from Space Battleship Yamato 2199.
WARNING: Mildly NSFW.
Satsuki and Ryuko from KLK.
Hotaru and Chibiusa from Sailor Moon.
Fang and Lightning from FF13.