Japan’s World Cup expectations soar with Samoa next in their path

• Japan have won their past four World Cup games• We have to think we are starting at zero, says captain LeachThere has been a routine question asked of the leading nations this week: how do you rate Japan’s prospects after the victory over Ireland? It showed how one result can radically transform opinion and expectation, and the New Zealand flanker Sam Cane carefully fielded it by saying: “It will be exciting to see how they go against Scotland.”Japan have to overcome Samoa first in Toyota on Saturday and a danger after their thrilling if, to the outside rugby world at least, unexpected victo…