Tokyo's Haneda Airport doubled its international flights to 80 a day from Sunday in a bid to court international travellers and boost capacity ahead of the 2020 Olympics.
Haneda, the fourth busiest airport in the world, has better access to the Japanese capital's downtown than suburban Narita airport, which has until now been the major international gateway.
"I live in the UK and I am very happy," said Takahiro Kato before he got aboard a flight for London.
"It's going to make my life easier. It's much more convenient to come to Japan now."
Many of the new flights out of the expanded Haneda terminal will operate during the daytime, which is expected to increase its appeal to international flyers.
Japan's transport ministry is aiming to boost international flights at both Haneda and Narita airports in anticipation of an influx of visitors for the 2020 Olympic Games in Tokyo.
"Not only Tokyoites but people from all over Japan will be able to benefit from it and easily fly all over the world," said Japan Airlines (JAL) president Yoshiharu Ueki.
"I have always said that I wanted Haneda to become a gateway between domestic and international lines, and I think we made the first step towards it today."
JAL has five of the 16 new international take-off and landing slots at Haneda.
It had expected to share the slots evenly with its rival All Nippon Airways (ANA), but the government gave 11 to ANA, which has routinely criticised once-bankrupt JAL's massive bailout.
"By better linking domestic and international flights, we can gain back travellers from regional airports in Japan, who have been using airports overseas instead," said ANA president Osamu Shinobe.
"The business chance is now in our hands."
The distance between the two airports has long put off travellers heading overseas from Japan, who would instead fly from their local airports to destinations such as South Korea's Incheon to transfer to longer-distance flights.
ANA said last week it would buy 70 new planes worth $16.4 billion, collectively the biggest orders in its history, as the airline aggressively looks to expand its international presence, which has included grabbing the lion's share of the coveted new landing spots offered at Haneda Airport.
The airline will buy 40 planes from Boeing, its major supplier, and one that has had a virtual stranglehold in Japan for decades, and 30 from Airbus, to expand its fleet ahead of the 2020 Tokyo Olympics.