We stayed at Sai 3/F apartment for 4 nights. Location was convenient, just a few buildings away from Tawaramachi station. The apartment is very modern and chic, like living in a Ikea/Muji showroom. It is also very clean and loaded with amenities that came in handy for us (washer/dryer unit and ironing board and iron). Our unit has 2 separate rooms with a sliding door separating one set of beds from the other main room, each room equipped with separate TV and A/C unit. My kids loved this feature of personal space. 4 single beds and linen were clean and comfortable.
A great place for a family of 4 when visiting Tokyo!