Three ships which left port in June returned with 43 minke whales and 134 sei whales, the number stipulated beforehand, according to the country's fisheries agency.
Japan is a signatory to the International Whaling Commission's (IWC) moratorium on hunting, but exploits a loophole which allows whales to be killed in the name of scientific research.
The studies are "necessary to estimate the precise number of (sustainable) catches as we look to restart commercial whaling", agency official Kohei Ito told AFP.
Tokyo claims it is trying to prove the whale population is large enough to sustain a return to commercial hunting for a traditional source of food.
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But Japanese consumer demand for whale meat has declined significantly over the years, raising the question of whether such hunts still make economic sense.
Foreign pressure on Japan to stop whaling has only made conservatives and politicians more resolute about continuing. It is a rare thorny issue in Tokyo's otherwise amiable diplomacy.
Japan cancelled its 2014-15 hunt, only to resume it the following year under a new programme -- saying the fresh plan is genuinely scientific.
Its hunt in the Antarctic has seen clashes on the high seas between Japanese whalers and animal rights activists.