George Takei and his longtime partner, Brad Altman, were wed Sunday evening in a Buddhist ceremony in downtown Los Angeles.

"All I can remember is what the priest said," Takei told PEOPLE after the ceremony. "That this moment will never happen again. It's something to savor."

Nearly 200 of the couple's friends attended the event, which began as a kimono-clad koto player plucked out tunes on the ancient Japanese stringed instrument. Afterward, the couple sipped sake from red lacquer cups, then said their vows to one another while standing within a circle of yellow rose petals.

A Scottish bagpiper led Takei, 71, and Altman, 54, to the reception on the grounds of the Japanese American National Museum. On the way, the couple, along with their maid of honor and best man (Takei's former Star Trek co-stars Nichelle Nichols and Walter Koenig) flashed the "live long and prosper" hand sign to photographers and friends.

"I was fighting back the tears," said Nichols, who played Uhura on the Star Trek series. "But they came oozing out anyway. I'm so happy that they're both able to legally proclaim their commitment to one another after spending the past 21 years together."

In May, Takei announced his plans to wed after California's Supreme Court allowed gay marriage under the state's constitution.