Using a Shinkansen reserved seat ticket in 2026 is a two-step process involving the Ticket Gate and the Train Carriage. First, when entering the Shinkansen-only area of a station, you must insert both your base fare ticket and your limited express (reserved) ticket into the slot at the gate simultaneously (or scan your QR/IC card if using the Smart-EX app). The gate will return them to you; do not forget to take them. Once on the platform, look for the markings on the floor that indicate your car number (e.g., "Car 7"). Your reserved ticket will show a car number and a seat number (e.g., "Car 7, Seat 12-A"). Reserved cars are distinct from "Non-Reserved" cars (Jiyu-seki), so ensure you are in the correct section of the train. In 2026, if you are carrying "Oversized Baggage" (total dimensions over 160cm), your reserved ticket must specifically include a "Baggage Space" reservation, or you may be subject to a 1,000 yen fine and required to move your bags.