With a testing match under their belts, Emblen was happy to know what now needed to be done before the team meet Belarus on July 26.
"We were given a footballing lesson tonight not just in the way Japan played through the thirds but also in the way they closed down and pressed," Emblen said.
"There was some good goalkeeping and last ditch defending on our part as well as some gilt edged misses on theirs- we rode our luck a bit.
"The boys looked rusty but I thought we showed that dogged New Zealand spirit and we've shown that we are hard to beat but we need to add some quality to that now while keeping that mentality.
"Our ball retention and speed of pass must improve but we have at least some time and a page of things to work on - this morning that page was blank.
New Zealand's next Olympic warm up is on Saturday night against South Korea in Seoul, with the Football Ferns playing their first warm up match against Canada in Switzerland later that night.
Japan 1 (Kenyu SUGIMOTO 71')
New Zealand 1 (Dakota LUCAS 90+4')
Halftime: 0-0