The Japanese scored two early goals and then kept the 2015 champions at bay for the rest of the game.
Both teams had won their opening match on Saturday. The Japanese upset Australia 2-1 while Britain, a finalist last year, had defeated New Zealand 3-2.
The Japanese were the stronger team and had a good start when they scored their opening goal in the 10th minute through a field attempt by Kosei Kawabe.
This gave the Asian team greater control of the match and in the 29th minute increased the lead through a penalty stroke conversion.
Raiki Fujishima easily scored with a low flick.
As the second quarter came to an end the British side earned their first penalty corner of the match.
Stuart Rushmere sent a direct drag flick to the right to deduce the deficit.
From then on it was a battle of the midfield as both sides tried had to get the goals. Both had ample chances to increase the tally but desperate defending saw them maintaining the scoreline.
Japan went on to snatch their second full points in the tournament
Britain coach Jon Bleby gave credit to the Japanese for their good display.
“Japan is a good team and played very well. They took their chances and made sure their defensive play was up to mark.
“I must say that we too had a good game and was in the match at the fourth quarter to get the goals. But unfortunately, we failed to finish the moves we created,” he said.
Japanese coach Hiroki Sakamoto was happy to have collected full points again.
“It was a good performance and we played much better. Still, there are several areas for us to improve on. We want to keep the momentum going into the next match.
“The win will boost the confidence of the player greatly,” he said.
Japan play India while Britain will face Australia in the next round of match on Tuesday.