score:1
TL;DR: Roppongi is one of Tokyo's main nightlife hubs and you can find pretty much anything you're looking for: flashy or underground, expensive or cheap, above the board or super sleazy. It's also Tokyo's main expat nightlife area in both good (lots of ladies who like foreigners) and bad (a fair few clip joints out to fleece unsuspecting tourists), but as long as you pick the places you go, you're not going to run into any trouble.
Quoting (mostly) myself from Wikivoyage Roppongi:
Roppongi is the place to be (late) at night, although you might expect to encounter some non-Japanese street promoters, urging you to just take a free look in their strip clubs, and occasionally trying to shake your hand. The scene continues late into the night, and many bars, clubs, and discos are open until 4–5AM when the first trains run in the morning.
There are innumerable watering holes, and generally speaking, first floor and ground floor establishments cater to young adults and foreigners while higher stories feature more exclusive clubs aimed at slightly older Japanese males. An ID is required by many clubs, so bring along your passport. Note that many of the clubs are very small, and leaving and re-entering without paying the entry charge again is often not possible.
Beware of touts inviting you into clip joints, some of which will go so far as to spike your drinks to wring you dry. Avoid going to a bar you've never heard of with someone that you didn't know before your journey. Leave your credit cards at home, since in a bid to combat fraud an increasing number of bars accept only cash anyway.