Tucked away in a cozy corner of Tokyo's Setagaya Ward, million-selling singer and rapper Soulja twirls an unsmoked cigarillo in his fingers while nodding his head to a hip-hop beat. "Yeah, that's good. I like that," he says to the man beside him, who is seated in front of a sound board and a colossal computer monitor. They are in a studio putting together Soulja's latest single, a collaboration with J-pop superstar Issa, of Da Pump fame. And the man next to Soulja, sporting a shaved head and dressed all in black, is songwriter and producer Jeff Miyahara.

You could be forgiven if the name Miyahara doesn't instantly ring a bell — but perhaps these names will: Crystal Kay, Namie Amuro or Thelma Aoyama. How about Timbaland, Pharrell or Boyz II Men? Miyahara has made beats for all of them. Over the years, Miyahara has accumulated quite a back catalog of hugely successful artists he has worked with, and has quickly become one of the hottest and most sought-after producers in the Japanese music scene.

"Jeff is the man," says Soulja. "He's definitely my favorite producer to work with."