*Australian dollar plunges to 5-day low of 0.7062 against greenback

*Japanese yen soars to new multi-week highs of 83.31 against Swiss franc and 125.36 against euro

*Japanese yen edges up to multi-week high of 68.02 against aussie

*Japanese yen rises to 5-day high of 54.28 against kiwi and 4-day high of 79.09 against loonie

Yen strengthens against majors