Series of eroge by Lilith[1] and hentai OVA adaptations by Pixy[2] and ZIZ[3] featuring ninja girls in skintight costumes.
[1] http://www.lilith-soft.com/
[2] http://www.pixy-soft.com/
[3] http://www.ziz-entertainment.com/
The following tags implicate this tag: action_taimanin, taimanin_asagi, taimanin_asagi_2, taimanin_asagi_3, taimanin_asagi_gaiden, taimanin_asagi_kessen_arena, taimanin_asagi_zero, taimanin_kurenai, taimanin_murasaki, taimanin_rpgx, and taimanin_yukikaze (learn more).