Ranma falls into the Cursed Spring of Jusenkyo, all right, but this time he's turned into one of those Calimari of Justice, a Nendo Kata, as well as the souls of the others trapped in the spring... Genma is going to have an interesting time fulfilling that promise to Soun now!
When Ranma fell into the Nyannichuan, the shock of the change caused her to lose control of her body, and she fell back into the pool, drowning. But before she died, 3 hollow rocks appear and levitate Ranma out of the pond. One day later, the rocks have finished their work, and there are now 3 girls newly created from the aliens in the rocks and Ranma, the spirit of his unborn sister and the spirit of the girl who drowned in the pool. How will Ranma, Ranko and Kikuko fit into the Nerima life? They're not even human any more, being partly Nendo-kata, an all female alien race that has strong moral beliefs, and interesting psionic powers. Are there more of their kind around?
During their fight, Ranma falls into the Nyannichuan and nearly drowns before three alien beings arrive to rescue him, engaging in the timeless Nendo-kata ritual known as the Crossing Over. Twenty-four hours later, Genma winds up with three daughters: Ranma, Ranko (born of the spirit of Ranma's would-be twin sister, who died stillborn in Nodoka's womb), and Kikuko (born of the spirit of the girl who drowned in the Nyannichuan 1500 years ago). And now, the three Tendou sisters are about to meet the three Saotome sisters...!