"However, there is [still an] underlying concern about the decline in Japan's population, so if I were to talk about areas outside of Tokyo, I would think it's neutral to slightly positive," he added.
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Asia's commercial real-estate investment market is thriving this year. Transactions in Asia Pacific over the first three quarters have reached $89.6 billion, up 25 percent on year and are expected to reach $110 billion by year end.
According to property research firm Jones Lang LaSalle, demand from Japan has comprised a fair chunk of this fresh demand. Deals in the third quarter climbed 139 percent on year, amid interest from both domestic and offshore investors.
However, competition remains strong in the Asia Pacific region, with many other players, including Hong Kong conglomerate Cheong Kong, striving to gain a piece of the burgeoning market.
Kawahara said he planned to tackle heightened competition in Indonesia, for example, by branching out into city suburbs, rather than focusing on city centers, where commercial real estate markets are already saturated.
"Our model is centered more around the suburbs, just like we succeeded in Japan. We know motorization is spreading quickly in Indonesia so we are planning to encompass larger areas, where people can easily get to by car," he added.
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Japanese publicly traded real estate trusts raised $4.9 billion in the first eight months of the year, Reuters data showed, almost three times more than the same period last year.
—By CNBC's Katie Holliday: Follow her on Twitter