Head Coach Gareth Williams has also drafted in rising stars Ben Roach (Cardiff Blues) and Angus O'Brien (Newport Gwent Dragons) as he plots the downfall of USA, England and Kenya in another demanding pool in Hong Kong.
Rhodri Williams' inclusion ensures Wales have plenty of options in the crucial scrum half position with Tomos Williams and Rhodri Davies having already established themselves on the circuit but the Scarlets scrum half goes to Hong Kong with the full blessing of the national squad.
Wales assistant coach Rob Howley said he will be keeping a close eye on Williams' progress.
"It's great to see the Scarlets have released Rhodri to represent his country at the prestigious Hong Kong Sevens. As a national squad we see the Sevens inter-action in his season as a potential springboard to return to the levels we know he can achieve," he said.
"We appreciate the world class levels required on the Sevens World Series and it will be an excellent challenge for Rhodri and we will be monitoring his progress as we do with numerous developing players in the sevens environment."
Wales Sevens squad for Hong Kong and Japan
Jevon Groves (WRU capt)
Sam Cross (WRU)
Craig Price (Scarlets)
Ben Roach (Blues)
Rhodri Davies (Llandovery)
Rhodri Williams (Scarlets)
Tomos Williams (Blues)
Angus O'Brien (Dragons)
Dan Fish (Blues)
Adam Warren (Scarlets)
Tom Williams (Blues)
Luke Morgan (Dragons)
