The Happiest Mousse (ムースのしあわせ Mousse no shiawase?) is the 99th chapter of the manga it is also the fifth and final chapter of the Mousse Returns Arc. The fight begins, but Mousse's new weapon that Shampoo made seems to keep backfiring and injuring him instead. At this rate Ranma is sure to win, but Mousse refuses to give up.