Japan secured qualification for next year's World Cup after being crowned Asian 5 Nations champions on Sunday.
They will be in Pool B at England 2015, joining Scotland, South Africa, Samoa and USA.
Their first match of the tournament will be against the Springboks in Brighton on September 19 next year.
A 49-8 victory over Hong Kong at the National Stadium in Tokyo - the game was watched by a 40,000 crowd - booked Japan's World Cup place.
Japan head coach Eddie Jones said: "I t was a difficult game, but I was pleased with how we finished the match as we showed patience and discipline.
" We want to make the quarter-finals at England 2015, and we are preparing to achieve that goal."