The No 3 seeds defeated Japanese Gengo Kikuchi and Shunrou Takeshima 6-2,7-6 in the first round.
They will play wildcard pair Yuhei Kono and Yuto Sakai of the hosts in the nextround.
In another match on March 14, Japanese Takuto Niki and Kaito Uesugi caused anupset by beating No 1 duo Gao Xin and Li Zhe of China 7-6, 3-6, 10-3.
Earlier, Sho Katayama and Arata Onozawa of Japan beat ChineseTaipei’s Huang Liang-chi and Lin Wei-de 6-2, 6-4.
In the singles event, no surprises as all high seeded players qualified for thenext round.
No 1 Chinese Li Zhe easily won 6-1, 6-1 over Thailand’s Pol Wattanakul,while No 2 Max Purcell of Australia struggled but beat ShoShimabukuro 2-6, 6-2, 6-4.
No 3 Takuto Niki beat his Japanese countryman Yunosuke Takana 6-4, 6-4.
Nam will play his second round singles match today against qualifier LeeJea-moon of the Republic of Korea who defeated No 8 seed JumpeiYamasaki 6-1, 6-3 on March 13.-VNA