Having scored early on with a deft finish over the advancing Ayaka Yamashita, Ellen White doubled her tally late on to wrap up a deserved win over a Japan side that beat England in the semi-finals in 2015.
Karen Bardsley made a brilliant save in the opening minutes, but was rarely tested in England's goal as Phil Neville's side claimed maximum points from the group stage.
England coach Phil Neville made eight changes to the team who beat Argentina but it did not cause too much disruption as they dominated a Japan side lacking a cutting edge in attack.
While England will wait to see who they will face in Sunday's last-16 game, second-placed Japan will take on Canada or Netherlands.
