Should I buy a Shinkansen Rail Pass if I visit Japan?
Shinkansen Rail Pass is quite expensive. The cost is slightly cheaper comparing with Shinkansen round trip between Tokyo and Osaka. If you are planning to have a round trip between these 2 cities, then you should definitely consider to get a Shinkansen Rail Pass. If your Shinkansen trip is shorter than that, you probably better estimate the railway cost before get the Shinkansen Rail Pass.
Instruction: Should I buy a Shinkansen Rail Pass if I visit Japan?
Context: 
Response: Shinkansen Rail Pass is quite expensive. The cost is slightly cheaper comparing with Shinkansen round trip between Tokyo and Osaka. If you are planning to have a round trip between these 2 cities, then you should definitely consider to get a Shinkansen Rail Pass. If your Shinkansen trip is shorter than that, you probably better estimate the railway cost before get the Shinkansen Rail Pass.