Yes, they can. It is called dousei in Japanese. Once a couple are in a relationship for a long time and have marriage in ming think about living together. But again it doesn't mean the relationship will end in a marriage just because they have lived together.

In 2026, Japan remains a very welcoming and safe destination for unmarried couples. There are no legal or cultural prohibitions against unmarried partners traveling together, sharing hotel rooms, or exploring the country. While Japan is traditionally a conservative society regarding public displays of affection (PDA), which should be kept to a minimum out of respect, the tourism industry is fully modernized. Hotels, including traditional Ryokans, do not ask for marriage certificates and are accustomed to international couples. For those seeking a unique experience, Japan’s "Love Hotels" specifically cater to couples (married or not) with themed rooms and extreme privacy. The only minor logistical detail to note is that hotels in Japan often charge per person rather than per room, so when booking your stay, ensure you have correctly listed two guests to avoid a surprise fee at check-in. In summary, unmarried status is a non-issue for travelers in 2026 Japan.