First of all, you have to collect your key from a different location. So instead of a 12 minute flat walk from the station, you have a 10 minute walk to pick up the keys then an 8 minute walk to the guesthouse. This includes carrying your stuff up and down the steps of an overpass, so it's a little inconvenient. Fortunately, you don't have to do this in reverse in order to check out.
The Japanese townhouse itself is really great - the equivalent of a bedroom, kitchen, lounge and reading room. We are a family of four, so we had two futon beds in addition to the two proper single beds. Plenty of room for all of us. (There's a washing machine, but it takes forever to dry your clothes and there's not really anywhere to hang them up to dry.)
The location is quiet - there's maybe one restaurant and one convenience store (plus a cult headquarters) on the walk from where the station block ends to the house. Worth it, I think, because of the spacious accommodations.