These two draincovers are from Ise in Mie Prefecture and show pilgrims in the Edo period who descended on the shrines at Ise by their millions.
At that time, travel for commoners was restricted, but pilgrimage was about the only reason you would be allowed to travel. There were many pilgrimage sites across Japan, but a very popular one, possibly the most popular, was Ise due to its reputation as a site for prayers for good harvest. Each year hundreds of thousands would go to Ise, and in a few years there were literally millions of pilgrims.
Japanese pilgrimage has been seen as an early form of tourism, with many guidebooks being printed. Some aspects of contemporary Japanese tourism seems to have roots in pilgrimage:- the package tour, omiyage, etc. Notwithstanding the religious aspect, it was a form of tourism and around each pilgrimage site huge "entertainment" districts served the needs of the pilgrims. At Ise, a single brothel was believed to have had over 1,000 girls working there.