The Japan international was unhappy with his debut campaign in England.
"I wasn't satisfied with my overall performance but I played well in the second half of the season and started to get more and more confidence," he told Sports Illustrated.
"Hopefully, I can keep that going at the Confederations Cup.
"In this business, you need to be like Rooney or Van Persie and prove yourself if you want the ball.
"I want to be a player like them, which means I need results."