Based on a true (ish) story and someone most longterm foreign residents (lifers) know, or know of, in Tokyo.
American graduate flies out to Tokyo in the earlier 90's gets job as a crime reporter on the local English language newspaper, but because he's foreign he dispels with the caution and goes in very deep with the police and the yaks.
Writes book in the 00's, 2020 and HBO buy the rights and get Michael Mann to direct..