Ranma ½, part 9 number 3

Part 5: For The Love of Sauce: Ranma is still being nice to Ukyo rather than tell her how he messed up her sauce when he was really young.

Part 6: The Truth About The Truth: Ranma seems to have entered an agreement when he was young to take care of Ukyo for the rest of her life. Akane, of course, is furious at Ukyo staying at the Tendo's. Ranma tells Akane what really happened, then he finally tells Ukyo who doesn't believe it. Nabiki then steps in and says Akane and Ranma are already married. Akane threatens to have Ranma thrown out of the house if he doesn't go along with the ruse.