This place was perfect for my needs! You can read more below.
LOCATION
It is a bit of a walk from the nearest station (Shin-Koenji) BUT it's actually a nice walk. And very safe, per Japan. I really enjoyed having the 10-12 minute walk through the residential part of Tokyo with the trees rustling and the cicadas chirping. The bus station for Shinjuku/Shibuya is also a close walk (4 minutes). There are a number of shrines in the area, as well as a restaurant (清水屋) that makes incredible fried manju!
CLEANLINESS
Super clean! You really can't ask for cleaner.
AMENITIES
It's really nice to not have to bring your own towel! Shampoo, conditioner, and body wash are all provided. Just bring your toothbrush and toothpaste. If you're in Japan for a long duration, the washer/dryer and kitchen will be very useful.
HOST
Sangwon was super responsive to all the questions I had, and provided helpful PDFs of house information, nearby restaurants, and an onsen as well! :)
LAYOUT
I stayed in room 104, which is next to the stairs, the washer/dryer, and shower room. FYI: 102 is next to the bathroom, 103 is next to the sink & kitchen, and 105 is right next to the stairs. Because you share the house with a number of other guests, you might want to consider picking a room that makes sense for your schedule if you're sensitive to sound. For instance, I always got back late so being next to the shower room was nice as people rarely showered in the morning.