In fact, as NPR's Bill Chappell reported in 2014, the International Court of Justice ruled that its whaling program - which has been going on since 2005 and killed thousands of minke whales, according to the ICJ - has generated only limited scientific output.
The Fisheries Agency said the five-ship fleet finished its four-month expedition without major interference from anti-whaling activists who have attempted to stop it in the past.
"It was great that we have achieved our plan".
Three Minke whales are pictured on the deck of the Japanese whaling vessel Nisshin Maru inside what Sea Shepherd Australia says is an internationally recognised whale sanctuary in this handout image dated January 5, 2014. Norwegian officials estimate there are more than 100,000 North Atlantic minke whales - which are not an endangered species - off the long ragged western coast of Norway where the hunt takes place.
Heather Sohl, WWF Chief Adviser on Wildlife, said: "30 years since the worldwide moratorium on commercial whaling came into effect, it is unacceptable that so-called scientific whaling is still putting whales, such as the 300 minke whales caught by Japan, at risk".
Since 1986 there has been a moratorium on hunting whales Under the International Whaling Commission, to which Japan is a signatory.
Japan intends to cull 4,000 more whales over the next 12 years as part of its "research". Officials in Japan must submit its proposed catch to the group IWC.
"Each year that Japan persists with its discredited scientific whaling is another year where these wonderful animals are needlessly sacrificed", Kitty Block, the Humane Society International's executive vice president, told DW.com.
She went on to state that there is "no robust scientific case for slaughtering whales", adding that "commercial whaling in this or any other guise does not meet any pressing human needs and should be relegated to the annals of history".
Critics say it's a dying industry, but Japan's government has spent large amounts of tax money to sustain the whaling operations, saying it's a Japanese cultural tradition that must be preserved.