Window washers in Santa Claus costumes work in a gondola at Tokyo Skytree in the capital’s Sumida Ward. (The Asahi Shimbun)

Window washers are going to great heights to get into the Christmas spirit, donning Santa Claus suits to do their gravity-defying work outside Japan's tallest building.

The Tokyo Skytree cleaners are making unscheduled appearances in the suits in an annual year-end tradition that began in 2016 at the 634-meter building in the capital's Sumida Ward.

Children spotting the Santas at the Tembo Galleria located 450 meters up rushed to the windows to wave at their unexpected guests on Dec. 6.

The Galleria’s 627 windows are washed monthly. It takes workers about seven days to clean them all.