This is an unbelievably cheap deal for flights this month and in June to Helsinki, Finland. Flights stop in Tokyo for a short layover and then onto Finland. Bags, meals and seat selection are included in this fare.
Find all the cheap dates on Google Flights then enter them directly into Aunt Betty (Flight Centre company). I'm seeing 6 cheap outgoing flights in May and 1/2 in June, and plenty of dates to return.
Aunt Betty is offering $80 off flights to Europe using code MUMSDAY80 which pairs perfectly with this already cheap deal. Make sure not to select the $717 flights as those go back via Jetstar so you'll be up for paying bags, meals, seats etc on that. Screenshot of fare
Also for $763, you can schedule a stopover in Tokyo for a few days if wanted. Google Flight Itinerary. You'll probably have to call BA or possibly book it on BA's site.
$50 off Return International Bookings (More for North/South America, Europe) @ Aunt Betty
Wow, great find OP. Going to Europe is getting cheaper and cheaper