There were four times as many flows in January than in the previous month, according to Morningstar.
Asset managers reduced their cash holdings for the second consecutive month, according to the State Street Global Markets Risk Appetite Index.
Flows into safe-haven sectors reversed in November, according to State Street institutional investor indicators.
The positive inflows into bonds and equities during the third-quarter belied an overall mixed outlook.
There were net inflows to open-end funds in Japan of ¥948.4bn in August, Morningstar data show.
Fixed income witnessed net inflows of S$888.25m during the second quarter, data aggregated by Morningstar show.
According to Morningstar Direct data, inflows to Japan funds in July hit their highest level since December.
Overall ETF inflows in Asia came in at $29.73bn despite a mixed market backdrop.
Inflows into sustainable funds slowed during the second quarter but still outstripped conventional fund flows.
Eight of the 10 highest-performing funds came from the sector, with Matthews China returning 10.43%.