It took four workers three hours to carry the massive mask on ropes up the 57 m-high (187 ft) white statue of the Buddhist goddess Kannon - the Goddess of Mercy - at the Houkokuji Aizu Betsuin temple in Fukushima Prefecture.
They then unfurled the mask made with pink net fabric, measuring 4.1 m by 5.3 m and weighing 35 kg (77 pounds), across the lower half of the statue's face.
The statue, built 33 years ago, is hollow with a spiral staircase that can be climbed to the height of the goddess' shoulder. People visit the statue, which is holding a baby, to pray for the safe delivery of babies and to ask for blessings for their newborns.
Temple manager Takaomi Horigane said workers came up with the idea for the face mask in discussions on the restoration of the statue after it was damaged in an earthquake in February.
Horigane said they plan to keep the mask on the statue until the Covid-19 situation is under control in Japan.