The place is great. About five minutes-walk from the station and two stops from Shibuya. The place is perfect for two people. I guess it could also accommodate four, but bear in mind that it is very small (although comfortable).
The host will provide with instructions on how to get to the flat. Ignore them and follow Google Maps, it's quite easy to get there. Also ignore the train and subway prices in the instructions as they are all (very) wrong.