The Japanese men got off to a losing start at the world team table tennis championships on Monday, falling 3-2 to Greece.
Jun Mizutani won twice for the host country, but Seiya Kishikawa suffered two defeats and Kenta Matsudaira one as three-time bronze medalist Japan tripped up in its Group C opener.
The top three in each of the four six-team groups qualify for the knockout phase. Japan plays Romania on Tuesday.
On the women's side, Japan defeated Bulgaria 3-0 in Group B as London Olympic silver medalists Sayaka Hirano and Kasumi Ishikawa, and Saki Tashiro rattled off three straight wins.