Here is a deal to Tokyo with Qantas. Prices start from $738 with the travel period stretching from 15 May to 19 June 2017.
Sydney to Tokyo – $767 (nonstop with flights landing at Haneda with B744 aircraft)
Melbourne to Tokyo – $738 (nonstop with flights landing at Narita with A333 aircraft)
Tokyo is serviced by 2 International airports – Haneda and Narita. Haneda is much closer to Tokyo CBD at 15km, while Narita is some 65km though accessible by two very fast train links taking about an hour travel time to Tokyo CBD.
To book jump on www.momondo.com
Happy travel :)