I stayed at Smile Home twice. 4 days in the beginning of my trip and 5 days at the end.
Others have probably mentioned it already, but this is a single floor, with 8 rooms and a shared bathroom (1 toilet for men, 1 for women and 1 shower for everybody). It might sound crowded, but I actually never had a problem. The people who stay there are usually respectful, given that they all recognize the situation/reality.
You never meet the owner but you might meet the staff who helps with maintenance, cleaning and administration for 1-2 hours per day (around noon). It is not a particularly great place but for the price it is worth it. The area is not touristic which is great, but it is not that far actually from the main points of interest (given that you will need to hop on many trains during your stay in Tokyo anyway). The carpet which covers the entire place was my main problem. The room is very basic but for Japanese standards rather spacious.
In general, an average space but very price worthy if you are not a picky person.