Even if you have a Japan Railpass, we suggest that you invest in the all-inclusive Hakone Free Pass offered by the Odakyu Railway.
The Hakone Free Pass lasts for a year. 
mnli hypothesis: The Hakone Free Pass lasts for a year.  premise: Even if you have a Japan Railpass, we suggest that you invest in the all-inclusive Hakone Free Pass offered by the Odakyu Railway.