Nodoka had caught up with Ranma and Genma in china, she tried to get Genma to stop at Jusenkyo but the idiot wouldn’t listen. While battling, Nodoka had fallen in so Ranma jumped in to save her, turning into Nodoka’s twin. Later they find both mother and daughter are pregnant from the god Kronos and the babies have great power. Ranma’s baby Hotaru has the greatest. (Sailor Moon Crossover.)