Is it a sequel? Not really (technically it would come last in the franchise—see below)
Buckle up! You’re going to: Tokyo
Who’s out? Everyone, unless you count Diesel’s measly little uncredited cameo at the end
Who’s back? No one
Who’s new—and noteworthy? Director Justin Lin; Sung Kang (Han)
Who’s just new? Sean Boswell (Lucas Black); Twinkie (Bow Wow); DK (Brian Tee); Neela (Nathalie Kelly)
The 10-second synopsis: Sean, a troubled American teen, is sent to live with his hardass dad in Tokyo, where he goes deep into the city’s drifting scene. Barely-memorable races and chases (and the requisite love triangle) ensue.
Please note (for continuity’s sake): Don’t ignore the introduction of fellow racer Han, who dies here—making the next three movies in which he appears turn out to be oddly placed (but seemingly contemporary?) prequels.