In Japan, the possession and sale of certain types of swords, including most samurai swords (katana), are regulated by the Sword and Firearms Control Law (刀砲刀剣類所持等取締法, Tōhō Tōkenrui Shoji-tō Torishimari Hō). The law categorizes swords into different classes based on their historical or cultural significance.

Generally, swords that are considered traditional or historical artifacts, such as genuine antique swords, are allowed for possession and sale but require appropriate licensing and registration. These include swords that are recognized as Important Cultural Properties or National Treasures.

However, the possession of non-traditional swords, replica swords, or modern-made swords without significant historical value, such as decorative or ornamental swords, is restricted or prohibited under the law.

The specific regulations and requirements for owning and acquiring swords in Japan can vary depending on the type of sword, its age, and other factors. It is advisable to consult with Japanese government authorities, such as the local police or the Agency for Cultural Affairs, for the most accurate and up-to-date information regarding the possession and sale of samurai swords in Japan.