Miko Mido, an 18-year-old descendant of the Miroku ninja clan, discovers her ancestral destiny when her grandmother reveals the ancient war against the perverse demons of the Shikima world. After her sister Miyu is abducted by the demon Kyomora, Miko utilizes forbidden arts to enter the demon realm for a rescue mission. Facing overwhelming lust and dark magic, Miko must embrace her hidden powers to save her sister and vows to master her abilities to protect her family from future demonic incursions.
Miko discovers the shocking truth about her origins: she is actually the daughter of King Seikima, the ruler of the Shikima world, while her sister Miyu is the true heir to the Mido clan. After using a legendary seal to rescue her father from imprisonment, Miko helps Seikima restore order to his realm and end the relentless attacks on her life. With the conflict resolved and her heritage revealed, Miko bids a bittersweet farewell to her father as he returns to rebuild the Shikima world.
Miko and Ning-ning journey to the secret Miroku village, where they encounter Yaku, a half-blood demon ninja. They discover that the traitor Kamiri and the rogue ninja Kugutsu have raided the village and stolen the legendary Zipang sword. After a desperate battle where Miko and Ning-ning use a fiery alcohol technique to rescue Yaku from a pleasure-absorbing water monster, the villains escape with the treasure. Now allied, the three ninjas vow to hunt down the traitors and reclaim the clan's precious sword.
Miko and Yaku confront the traitors Camiri and Kugutsu, who have stolen the Zipang, a legendary and sentient demonic sword of the Miroku clan. As the Zipang merges with Camiri to fuel its thirst for lust and power, Miko must embrace her half-Shikima heritage to unleash a devastating secret technique and destroy the cursed relic.
A mysterious transfer student named Fubuki arrives at Miko's school, revealing herself as a skilled ninja who has stolen a sacred Miroku clan scroll. The two engage in a high-stakes duel of erotic ninjutsu before the King of Shekim, where Miko's superior techniques eventually secure her victory. Impressed by Fubuki's determination, the King grants her the gift of blue blood, transforming her into a powerful Shekima and forging an unlikely friendship between the two rivals.
Cyborgs from the world of Injo attack Miko's school and kidnap her friends, leading her to discover a plot to destroy the Shikima Kingdom and kill her father. After surviving a treacherous trial in another dimension, Miko returns home to face a brainwashed Fubuki and the malevolent Taizhuten. By unleashing her latent half-demon powers through the Blue Vortex Attack, Miko exposes Taizhuten's true nature and saves her family from total destruction.