In 2026, the majority of Shinkansen trains—including the Hikari, Kodama, Sakura, and Tsubame—continue to offer both reserved (shiteiseki) and non-reserved (jiyu-seki) cars. However, a significant rule change applies to the fastest Nozomi and Mizuho services during peak holiday seasons, such as New Year, Golden Week, and Obon. During these high-traffic periods, these specific trains operate as "Reserved Only," meaning no non-reserved tickets are sold and passengers without a seat assignment cannot board unless they stand in the decks. For the rest of the year, cars 1–3 are typically non-reserved on most routes. To ensure a comfortable journey, especially with the 2026 rules regarding oversized baggage (which requires a specific reserved seat for any bag with total dimensions between 160cm and 250cm), booking in advance via the Smart-EX app or at a ticket machine is highly recommended.