Benjamin Cho’s best friends want to make it clear, one after the other, that everyone was Benjamin Cho’s best friend. That whenever or wherever they met him, which they often can’t remember exactly, they were only one of many, many others. Whatever the circumstances, once Mr. Cho appeared in their lives, from that day forward they spoke to him every day for years.

He was a fashion designer, whose intricately worked and often handmade pieces, painstakingly knitted or crocheted, were glamorously expensive, celebrated by Vogue and worn by pop stars and style icons. He was a D.J. whose weekly Smiths Night began as a friends-and-family affair and swelled to draw tabloid attention and every visiting star. But more than that, he was a social connector, a restless, relentless Zelig of downtown New York around the turn of the 21st century, who knew everyone and went everywhere, and was allergic to calling it a night.

“He’s the glue to a lot of downtown New York,” said Humberto Leon, a founder of Opening Ceremony, which opened its doors in 2002 with Mr. Cho’s designs front and center.

“Ben probably had 3,000 best friends,” said Alana Varel, a founder of Starworks Group, a public relations and brand development agency, who shared office space with him in the early aughts.