I did similar US-NRT-KIX-US 9 day trip in May. In NRT I was with my bags at T2 train station 30' after getting off the plane (arrived in J). Line at JR office looked 30' long. I exchanged voucher 2 days later. Used Pass on Tokyo-Osaka plus daily trips to Nikko, Kamakura/Yokohama, Himeji, Nara, Ex to KIX, and many short runs like Osaka-Kyoto or Tokyo-Ueno. I estimate saving close to $100 with pass. Make sure to download HYPERDIA by VOICE app, it's priceless.