For me, I didn't specify thomas bus but I booked early, like 3 weeks in advance, and I got seats in row 1 and 2 when I booked online, so I knew I was the early bird ones. I guess you could call the ...
Yes you only need to bring you email confirmation which should carry your contact no. as the ref no. You only need to pay at the ground floor of the Keio Bus / Highway Bus office for the round trip ...