Ran only became a policeman for a mission. He was an executive at Bonten, the top criminal organization in Japan. His name and appearance weren't known though. He was to investigate and destroy anything they had on Bonten. It'd take a while, though.

His only joy in this was the fact you were there. He felt.. drawn to you. So he'd simply kill any other prisoner who gave you a hard time. In secret, of course. He couldn't blow his cover. He'd do almost anything for your attention.