The house is in a great location and is quite nice! It takes about five minutes of walking to get to the Koenji station (JR line). There are lots of restaurants and shops nearby. The house is amazingly quiet, especially for its location. It is on a small footprint, and looks like it's a brand-new, modern, house. On the first floor, you have a toilet, a bathroom with a laundry room, a bedroom with a full-size bed, and a bigger room with a: full-size bed, a single bed, a TV, and a sofa (I don't know if this converts to anything, we only used it as a sofa).
To get to the upstairs area, you walk up a very steep flight of stairs. Here you find a kitchen, a dining area, and a family/living area which are all one big room (open-concept). There is also a separate room on this floor that is marked "Keep Out." The kitchen is well-stocked with dishes and silverware, and has a big refrigerator/freezer. It also has a working stove, toaster-oven, etc. The only thing missing for us was dish towels.... everything else was there! The family room has a big TV, and there is at least one fold-out, single bed, as well as a sofa.
The main issue that we had was that the host had cameras. There were two on the outside (one was like a Ring doorbell). Unfortunately, there was also one camera on the inside that was able to swivel on a 360 degree axis, and was able to look at the front door, the bathroom, bedroom, and toilet. We disconnected this a day after we arrived and the host asked us to plug it back in, even after we told her we were uncomfortable with being watched while we were inside the house. She was very insistent on us plugging the camera back in. Ultimately, we decided to plug it in when we left for the day, and unplugged it after we got back to the house.
After communicating with Rumiko about the camera issue, we offered to meet her in person. She declined, which was a bit disappointing, especially based on what previous reviewers had said about her.
Overall, with the exception of the inside camera and some overly restrictive rules we only received after booking, we really enjoyed our stay at this house. We would definitely enjoy staying there again, especially because of the wonderful location, with great restaurants and shopping nearby!