Ranma ½, part 9 number 7

Part 13: Prelude to Defeat: Cologne tells Ranma he'll never master the shishi hokodan. Ranma manages to do it once, but he has no idea how he did it.

Part 14: Unlucky Blow: Ranma figures out someone has to be depressed in order to unleash the technique. Cologne and Akane talk and Cologne tells her that the technique is actually dangerous to the user, but Ryoga and Ranma won't stop using it.