The Tokyo area's two international gateways are looking to push Japan's soaring tourist numbers even higher while also putting their Asian rivals on notice by adding more international flights ahead of the 2020 Summer Olympics.

Japan's biggest airport, Haneda, is set to add 50 international routes per day as, starting in late March, the government for the first time will allow aircraft to fly over central Tokyo during the day.

That would raise the number of international passengers at Haneda — officially known as Tokyo International Airport — by 7 million to reach 25 million per year, allowing the hub to leapfrog Kansai International Airport as the nation's second-busiest in terms of international passenger traffic after Narita International Airport in Chiba Prefecture.