Heading into the station core, we went to one of the larger reservation counters, where Lisa found a female agent she could understand better. (Lisa says she can understand women speaking Japanese much better than men.) She worked out that while the limited express was sold out, the local all-stops train is unreserved and would still get us out to Choshi with a few hours to do what we wanted. Furthermore, we could get on an "Airport Rapid" train to Chiba, then come back from Choshi only as far as Chiba before taking the Narita Express to the airport (and thus on to our hotel by shuttle bus). This was overall a better deal for us, because it meant we could go store our luggage at Chiba rather than at Tokyo, saving us around two hours of back-and-forthing to retrieve it. So Lisa booked the tickets and we hied our way down to Chiba.
Exiting the Chiba station, we looked for lockers. Good news: Several of the large lockers were available. Bad news: while internally they were large enough to hold my bag, the doors were too narrow for the bag to fit into the locker. I had to partially unpack my bag to get it to compress thinly enough to fit through the door. The ten minutes or so we spent fussing over luggage meant that we couldn't even try to get on that limited express train to Choshi (it had been gaining on us from Tokyo). That train has unreserved standard seats as well as reserved and Green cars, and we might have been able to grab a couple of seats, but we'll never know.
Anyway, with 40 minutes or so to kill before the local to Choshi, we went looking for breakfast. However, we were unable to find much close and convenient to Chiba, so instead we grabbed a couple of breakfast pasteries from a cafe next to the station and then bought bento boxes, rice, and drinks from stores in the station, and headed up to the platform for the nearly 2-hour slog to Choshi.
