Ninja

In the shadowy world where the Koga and Iga clans' territories meet, danger lurks as darkness falls. A mysterious parasitic threat emerges, targeting the skilled female warriors who navigate both desire and duty. When one of their own begins to show troubling symptoms after an intimate encounter, the others realize they're facing an enemy that attacks from within. As the infection spreads through their ranks, the women must race against time to uncover the source of this sinister affliction and find a way to combat it before it consumes them all. Their only hope may lie in the heavily guarded secrets of the Koga Institute, where answers to their survival might be hidden among forbidden research and ancient knowledge. (Source: AniDB - Edited for spoiler-free content)