From Narita air port

Narita air port --> Tokyo station 

1 hour by Narita Super Express or Keisei Super Express.

From Tokyo Station 

Tokyo Station  ---> Odawara station 

90 minutes by JR Toukaido Line or 40 minutes by JR Toukaido-Sinkansen Kodama Super Express.

Odawara Station ----> Minami-Onsen-sou bus stop.

50 minutes by bus.

From Shinjuku (by bus)

Shinjuku bus terminal ----> Toumei highway ---->  Minami-Onsen-sou bus stop.

90 minutes by Odakyu highway bus.

From Shinjuku (by train)

Shinjuku station ----> Hakone-Yumoto Station

90 minutes by Odakyu "Romance Car" Super Express.

Hakone-Yumoto Station ----> Minami Onsen-sou bus stop.

30 minutes by bus.

From Kyoto, Nagoya or Osaka 

Kyoto, Nagoya or Osaka Station  ---> Odawara station 

By JR Sinkansen Kodama Super Express.

Odawara Station ----> Minami-Onsen-sou bus stop.

50 minutes by bus.