Karakuri Ninja Girl (1996)

Ninja—they might be, but they're human, after all. They wish for an ordinary life in the city. Dreaming of their beautiful life together, two shadows leave the Ninja Country... They are Suzuka and Tsukikage. The chase is on, and once captured, they are subjected to an extremely erotic punishment. Have they learned their lesson? No. The joy of being "watched" drives them day and night, indoors and outdoors, everywhere. Ninja clan head Lady Youga finally has enough of the lovey-dovey lust energy running all over the place. Now that they are expelled, Suzuka and Tsukikage finally fulfill their dream of starting a sweet life, but they are interrupted by another escaped ninja, Sagari.