Sailor Moon S05 E07 Farewells and Encounters: The Transitioning Stars of Destiny

"In the name of the Moon, I'll punish you!"

Mamoru tells Usagi that he's accepted an offer to study abroad in the U.S., which will force them to have a long-distance relationship. Saddened at first, Usagi eventually decides to root for her boyfriend's dream and sends him off with a smile.