Some people break records for speed. Others — for sheer stamina. But this one left the world stunned.

In 2009, Masanobu Sato, a soft-spoken man from Japan, made headlines for setting one of the strangest records ever: nearly 10 straight hours of self-pleasure. His time — 9 hours and 58 minutes — remains unbeaten.

The event wasn’t a joke or a dare. It took place at San Francisco’s Masturbate-a-thon, an annual charity event aimed at breaking taboos around sexuality and raising money for health causes. “My imagination was the key,” Sato told reporters afterward. “And a lot of training.”

Sato, who worked for a toy manufacturer, said he treated it like an athletic challenge — swimming twice a week and gaining muscle for stamina. He even thanked his family, joking that they’d given him “good DNA.”

Years later, another contender claimed to surpass him, but without witnesses, the record still belongs to Sato — the man whose quiet focus turned an unusual act into a moment of global curiosity.

It’s a reminder that humans will always test limits — sometimes in the most unexpected ways.