Fuji Shibazakura Festival - How to get there

Hello, Good day!

Am planning to go Fuji's festival with my friend on a weekday. We've bought JR Pass for this Japan trip. Understand that Narita Express is covered within JR Pass. My question is - Are we able to go Kawaguchiko Station from Shinjuku station? The website itself says JR Pass only covered until Otsuki station but google map says Narita Express goes straight to Kawaguchiko station. Am very confused here. S.O.S please.

Google says:
https://www.google.com.sg/maps/dir/Shinjuku+Station,+Shinjuku,+Tokyo,+Japan/Kawaguchiko+Station,+Funatsu,+Fujikawaguchiko,+Minamitsuru+District,+Yamanashi+Prefecture+401-0301/@35.5951423,138.9550251,10z/am=t/data=!4m15!4m14!1m5!1m1!1s0x60188cd0d6b1ba1f:0x1c32a1f1ecacfdd5!2m2!1d139.6995788!2d35.690553!1m5!1m1!1s0x60196082ba47a9ff:0x9c7f0f27fe5cd448!2m2!1d138.769358!2d35.497984!3e3!5i3

Shibazakura says:
http://www.shibazakura.jp/eng/access/

Thank you!

Kind Regards