Yes, you can activate (exchange) your Japan Rail (JR) Pass at Osaka Station, but it is important to know exactly where to go, as it is one of the busiest hubs in the world. You must head to the JR Ticket Office (Midori-no-Madoguchi), specifically the one located near the Central Gate. There is a dedicated exchange counter for international tourists where you present your "Exchange Order" (MCO voucher) along with your physical passport containing the "Temporary Visitor" stamp. The office is typically open from early morning (around 5:30 AM) until late at night (11:00 PM), though the specialized tourist counters may have slightly shorter hours. It is worth noting that while Osaka Station is a major hub, many travelers find it more convenient to exchange their pass at the nearby Shin-Osaka Station if they are arriving via the Shinkansen, or at Kansai Airport (KIX) upon landing. Once activated, the staff will ask you for your desired start date, which can be that same day or a future date within 30 days. This allows you to secure your physical pass and immediately make seat reservations for your upcoming journeys across Japan's extensive rail network.