Golden Week
4 national holidays in 7 days! (late-Apr/early-May)
Golden Week is a collection of 4 national holidays within 7 days, that, combined with a couple of weekends, becomes one of Japan's three busiest holiday seasons, along with New Year (Shōgatsu) and O-bon (mid-August).
Expect trains, airports and sightseeing spots to get very crowded. Accommodation gets expensive and booked out well in advance in late April & early May.
The national holidays making up the Golden Week are:
29 April - Shōwa Day (Shōwa-no-hi) - the birthday of former Emperor Shōwa, who died in 1989.
3 May - Constitution Day (Kenpō-kinenbi) - the new postwar constitution came into effect on 3 May, 1947.
4 May - Green Day (Midori-no-hi) - dedicated to the environment and nature, because the Shōwa Emperor loved plants and nature.
5 May - Children’s Day (Kodomo-no-hi) - while it’s Children’s Day, Boy's Festival is celebrated on this day too, with families praying for the health and future success of their sons by hanging up carp streamers and displaying samurai dolls, both symbolizing strength, power and success in life. Girl's Festival is celebrated on 3 March.