The airline currently operates four flights a week to the Japanese capital from its Helsinki hub using an Airbus A340 aircraft.
Commenting on the impending launch of the additional flights, a Finnair statement said: "The addition of these flights will accommodate the demand from Japanese group travel which is at its highest level to Finland and Scandinavia during the four months."
Tokyo will be served on a daily basis by Finnair during the high season once the new flights come into effect.
Between June 13th and September 30th, the extra flights to Tokyo will run on Mondays, Wednesdays and Fridays, with the return flights taking off on Tuesdays, Thursdays and Saturdays.
Today (March 20th) marks the 85th anniversary of Finnair’s inaugural flight to the Estonian capital Tallinn.
The airline’s Junkers F13 seaplane took off from the Katajanokka terminal in Helsinki on March 20th 1924.