Cheerful and playful at their Shibuya studio, the four women of Speed have the energy and excitement of a debutant J-pop girl group. Yet their joviality masks the fact that they’re veterans of the most successful female Japanese group of all time. Between forming in 1996 and splitting up in 2000, Takako Uehara, Eriko Imai, Hitoe Arakaki and Hiroko Shimabukuro sold over 20 million records. Ten years later, as they prepare for a reunion tour, the women of Speed are all still in their 20s.

“We were talking with each other like ordinary 20-something girls over dinner,” says Uehara. “It had been about seven years since we’d stood on stage together, and I knew I needed to remember I was ‘Takako Uehara of Speed.’”