Charles Waterman here:
If you are calling to get your vaccination appointment today, and youy need the first one ASAP (because of travel or other issues) I recommend you try to book at one of the “mass vaccination sites” like the Kumamoto-Jo hall. If you do it by phone, be ready to struggle to understand the Japanese they will use and be prepared to very patiently and slowly spell every letter in your name if they ask you to. The gentleman who helped me this morning was very patient and got me a reservation
much earlier than I expected would be possible.
I don’t want him to get mobbed with calls, so I won’t post his name here. (I could hear several people taking on phones in the background)
I don’t know if it’s possible to get an early appointment online or not. If someone gets an early appointment using the online site, it would be helpful if you post that that’s also possible.