Season 6 - Random Rhapsody!
Episode #131 - Ranma to Ukyo ga Sōsu Sōai? (乱馬と右京がソース相愛?)
Ukyo after trying Akane's gruel.
Ukyo releases a secret sauce for her Okonomiyaki that she made with her father's recipe as a child. however, she gets depressed after tasting it, realizing how bad it is. however, Ranma remembers that he had interfered with the recipie after wanting a taste, and spilling the entire mix, and tried to fix it himself. however, after she eats akane's gruel, she gets ill, and temporarily moves in with the Tendos until she gets over her depression.
Ranma starts acting nice to Ukyo, due to his guilty conscience. however, Ukyo thinks he's behaving this way to honor a marriage proposal they made when they were kids involving the sauce. things get even more hectic when Nabiki announces that Ranma and Akane were already married. Ukyo decides to stay with the Tendos until the truth is revealed.