Perhaps take another look at the "JR ticket offices" web page you provided the link to - but this time use a laptop or desktop web browser. According to the web page as rendered on my PC, there are three T1 options and two T2-T3 options for this. From the timing, it would appear that Ticket Offices are staffed for this purpose "off hours", and during core hours the staff serving this function move to the JR Travel Center. Again, perhaps if rendering the web page on a mobile device, this distinction might not be clear.