Getting There & Away
For those wanting to start trekking as soon as they arrive from Tokyo, Keiō Dentetsu runs direct buses (¥2700, 2½ hours; reservations necessary) from the Shinjuku Expressway Bus Terminal to Fuji Subaru Line Fifth Station (aka Kawaguchi-ko Fifth Station; it does not operate in winter).
Buses run from both Kawaguchi-ko and Fujisan Stations to the starting point at Fuji Subaru Line Fifth Station (one way/return ¥1540/2100, one hour), roughly mid-April to early December. In the trekking season, buses depart hourly from around 6.30am until 7pm (ideal for climbers intending to make an overnight ascent). Returning from Fifth Station, buses head back to town from 8am to 8.30pm.
In the low season, the first bus inconveniently leaves Kawaguchi-ko and Fujisan Stations at 8.50am, meaning most trekkers will need to get a taxi in the morning to have enough time (around ¥12,000, plus ¥2100 in tolls), before getting the bus back. The bus schedule is highly seasonal; call Fujikyū Express or your hotel for details.
In the low season you should be able to find other trekkers to share a taxi at hostels such as K's House. Car hire is another option (particularly good if you're in a group), costing around ¥6800 per day plus fuel and tolls.
To get to the Subashiri Fifth Station trail, you can catch a bus from Kawaguchi-ko to Gotemba (¥1510), from where regular buses head to the Subashiri access point; Gotemba can also be accessed directly from Tokyo either by bus or train.