Representatives of Pacific nations are arriving in Tokyo to attend an interim ministerial meeting of the Pacific Alliance Leaders Meeting starting on Saturday.
The meeting gives nations the chance to discuss Pacific issues and aims to forge a bond of friendship between Japan and Pacific island countries.
Tonga's Prime Minister, Lord Tu'ivakano, arrived on Wednesday and has met investors from Tonga and Japan, including a Japanese confectionary company.
He will also meet members of the Tongan community living in Japan.
Last year, Japan declined to invite Fiji's interim prime minister to its Pacific leaders' meeting.
At the last minute Japan invited Fiji's Foreign Minister instead, who did not attend.
However, the Japanese High Commission in Fiji says Fiji's foreign minister has been invited to this year's meeting.
It could not confirm whether the minister will be attending.