Previously, I consulted with the airport customs and was informed that equipment without prior approval cannot be imported. For example, if someone brings unapproved equipment from Japan and attempts to import it, customs will seize the equipment. While there may be information online about temporary import procedures, this is for businesses to obtain approval domestically; it is not intended for individuals importing equipment.
Even radio stations that are not considered luxury goods are subject to inspection and taxation upon entry. Devices that have not been approved cannot be directly imported through customs. When approved devices are imported, proof of approval must be presented.CertificateYou can also request this from the manufacturer, for example, Yaesu has a small program that allows you to check if your device is approved.Certificate。
I don't know how to do it in practice.