Plenty of Lum-chan's! Urusei Yatsura : Season 5 Episode 21

Ran kidnaps Lum, and uses a 3-dimensional copier to craft a clone of Lum, with her intent that the clone will destroy Lum's relationship with Ataru. However, the clone is unable to go through with the plan. Ran makes several more clones, but they too fail. Soon, the clones have escaped along with the real Lum. Ataru soon finds himself dealing with 7 Lum's, though none are able to interpret who the real one is since they all look and think alike.

Mendo, Megane, Perm, Kakugari and Chibi then propose that Ataru let them each have one of the extra Lum's. However, they all have the same mindset and refuse to love anyone but Ataru.

Ataru soon after makes his way to Ran's place, who has a device that will erase the clones. However, Ran panics when the multiple Lum's arrive, and Ataru attempts to activate the machine...only causing it to malfunction and replicate Lum to a large number.