Matsuyama is the most populated city in Shikoku island and the capital of Ehime prefecture.
The main tourist attraction is Matsuyama castle which was built in 1603 and still has the tenshu(castle tower). However most of the tourists do not head to Matsuyama due to the castle but having a bath at the Dogo onsen(hot spring/spa).
Most of the public/private baths and spas do not allow a person with tattoo to use their facilities but the Dogo onsen honkan(main bathhouse) allows persons with tattoos.
Although it is very common to see a guy with tattoo in Europe but in Japan, having a tattoo means he is a Yakuza(Japanese mafia). When I saw an elder guy having a large colorful tattoo on his back at the main bathhouse, my legs were shivering. Of course, eventually nothing happened to me.