Japan won the International Rugby Board (IRB) Asia Rugby Series/Borneo Series in Kota Kinabalu after beating Hong Kong 38-14 in the final, Sunday.
Japan coach Wataru Murata said he was happy with the team's performance in the tournament as they conceded only four tries throughout the tournament.
"We made three conversions in the final match today. Basically, we controlled the game. Our defense was good and managed to block Hong Kong's tries," he told reporters.
Murata said the team had prepared well for every game in order to improve their skills since the team was preparing for the next Olympic games in London.
Japan made it to the final after beating South Korea 10-7, while Hong Kong beat Malaysia 22-17 in the other semi-finals to advance.
Earlier, Malaysia finished fourth after going down 7-33 to Korea while China came in fifth after thrashing the Philippines 34-0.
Meanwhile, Negeri Sembilan Wanderers won the Club Cup after beating Davetalevu 10-7, while Sandakan Rugby (SRC) Borneo Eagles took home the Club Plate after beating Combined Old Boys Rugby Association (COBRA) 26-10.