Haneda airport Express bound for kawaguchiko

Is the express bus bound for kawakuchiko (from haneda airport) via haneda airport express always full? We (7 adults) will b arriving haneda airport close to midnight on 25/11/2015 (Wednesday). I understand there is a direct bus @ 6.45am the next morning from haneda airport to kawaguchiko. Can anybody advise me the chances that there will b still available seats for the next morning express bus ? I don't see in the website that we can reserve the seats in advance . The earliest we can buy the next morning (6.45am) ticket will b by the time we reach haneda at midnight the day before.

You can reserve in advance. Try to call Fujikyu, or you can reserve online but in Japanese only.

By the way, Fujikyu says the first bus is at 6:55, not 6:45. Maybe you are looking at an out-of-date document?

Tq Firas for your info. I don't speak Japanese. So calling Fujikyu to reserve the ticket is rather impossible. But probably I can try online reservation. Can I have the link to fujikyu online reservation?

The telephone number of Fujikyu is also written on their English website so I suppose they can handle requests in English.

http://bus-en.fujikyu.co.jp/highway/detail/id/4/

Online reservation from either of those sites:
http://www.kousokubus.com/
https://secure.j-bus.co.jp/hon
You must pay by credit car (Visa or Mastercard). It is not possible for you to pay at a convenience store because you will arrive in Japan after the payment deadline.

We (7 adults) will be arriving Haneda airport close to midnight on 25/11/2015 (Wednesday).
I understand there is a direct bus the next morning from Haneda airport to Kawaguchiko.

When is your plane scheduled to land?
Do you plan to take a bus on 25 or 26 November 2015?

Buses for Kawaguchiko Station are much more frequently available from Shinjuku Expressway Bus Terminal than from Haneda Airport [HND].

The earliest bus from Shinjuku Expressway Bus Terminal for Kawaguchiko Station departs at 06:00, then buses depart every 30 minutes from 07:10 to 15:10.
A one-way bus ride on this route from Shinjuku to Kawaguchiko is expected to last for about 1 hour 50 minutes, and the one-way bus fare is 1750 yen per adult.

It is not easy to predict crowdedness during a peak sightseeing season, bus I guess you can take a bus from Shinjuku in the morning.
Both 25 and 26 November 2015 will be normal weekdays, and the previous weekend will be practically extended until Monday, 23 November (because this day is a national holiday), which may prompt people to make a long trip during the three days.

I don't see in the website that we can reserve the seats in advance.

Unfortunately it seems that you cannot book the 06:55 bus from HND International Passenger Terminal via website.
Regarding the bus route from HND, payment by credit card does not appear as your option on any of the two websites; the deadline for an applicant to purchase paper tickets at a manned window or convenience store is set at 17:00 on the day previous to the boarding date, and you cannot make it because you are expected to arrive close to midnight.

It is not possible to book a bus on this route via website for 7 adult persons at once.
So, even if someone can book a bus from HND for you, in order to secure all the seven seats in the one same bus, he/she has to book it on the phone, purchase the paper tickets later by the deadline and hand them to you.

I suppose trying to catch a bus from Shinjuku is worth considering.

Hi omotenashi, tq so much for explaining in such a detailed manner. It gives me a good understanding of the bus reservation / payment method. Thx again!