Japan has some of the strictest customs regulations in the world, and in 2026, prohibited items are strictly enforced. You cannot bring any meat products (including jerky or vacuum-sealed items), most fresh fruits, and specific vegetables without an inspection certificate. Most critically, certain over-the-counter and prescription medications common in the U.S., such as Adderall or those containing pseudoephedrine (like some Sudafed), are completely illegal and can lead to immediate arrest. Weapons, including small pocketknives with locking blades or self-defense sprays, are also banned. Furthermore, any item that violates trademark laws (counterfeit goods) will be confiscated. For a high-value 2026 trip, the "pro-move" is to check the "Yunyu Kakunin-sho" requirements for your specific medications and ensure you are not carrying any "prohibited" snacks that could result in a heavy fine or deportation at the border.