a 3.5-5.5 hour trip from Okutama via Honnitasan to Hatonosu station
West of Tokyo
take train to Takaosanguchi(高尾山口), 60min from Shinjuku
then ropeway, or lift, or climb to Takao-san. Takao-san is not very challenging, but a nice start, and along the way there are temples and shrines. When at the top of Takao-san, one can also decide to go further: to one, two or even 3 mountains nearby. See Jinbasan notes.
There is a nice bath inside the Takaosan-guchi-trainstation.
a nice 4 hours trip, seeing Sagamiko lake, climbing Sekirouzan, Onsen visit possible
North of Tokyo
take train to Tsukuba trainstation(つくば駅), 60min from Tokyo
then enter the shuttle bus (筑波山シャトルバス) to 筑波山神社入口(Tsukubasanjinjairiguchi), takes 36min
then either climb up (90min) or take the cablecar (5min)
from there you can eat, and visit both mountains (takes 15min to each), or walk other routes
When going down again via cablecar or by foot, there are several Onsen. 3 are part of hotels and only open for non-hotel-guests until 3pm. A small onsen exists and is free for normal customers, also after 3pm.
From Tokyo, take the train to Doi-station/土合駅, takes ~3hours
from there, go to 谷川土合口駅 (24min walk, or by car)
from there a ropeway and chairlift go upwards
from the plateau it takes 3 hours of walking to the top of 谷川岳. Good shoes recommended.