Children over 12 years old are legally allowed to purchase their own air tickets when traveling to Japan. However, for safety reasons, it is recommended that parents or guardians accompany their children to travel together, or choose to purchase tickets with additional services, such as luggage storage, seat arrangement, etc., to provide necessary assistance during the journey. At the same time, depending on the airline and Japan’s entry policies, you may also need to provide the child’s identity document, so it is best to inquire about relevant matters in advance.