Psshh–
Resized to 66% of original (view original)
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Artist's commentary
St. Gloriana's Golden Week Trip
It's St. Gloriana's Golden Week trip.
Source: https://www.pixiv.net/artworks/98014061
It's St. Gloriana's students boarding an express train for a golden week trip.
Source: https://twitter.com/omatiosake/status/1520212710197129216
golden week - the week from 29 April to 5 May containing multiple Japanese holidays.