Tokyo Station (Yaesu South Side) bus luggage

[Image for context](https://imgur.com/cPSwyuw)

I was in the process of reserving tickets from Tokyo Station -> Kawaguchiko Station and I get an email as part of the process. At the bottom of the email, it specifies that only one luggage per person, “including luggage loaded into the trunk room”. Not sure what the “trunk room” is exactly, but I’m assuming it’s the outside compartment where they stowaway luggage on the side of the bus?

I’ve been trying to find more information regarding this, but was not table to find an email to contact them by. They had [a section talking about luggage on their website](http://www.jrbuskanto.co.jp.e.wn.hp.transer.com/bus_info/notice.html), but I was still confused after reading that section. Still not sure if really only one luggage is allowed, or is it one luggage for the trunk/stowaway compartment + personal carry on.

Anyone have experience with these busses and can elaborate or clarify? I’m assuming it’s one luggage for trunk + personal carry on (i.e. bookbag), but I really just want to make sure.