The Good: the place is located very centrally, with Shinjuku just barely two stops away with a quick subway ride. There's a bakery just downstairs and several convenience stores across the road. It has a full table which is very rare in Japanese apartments, and a large patio/balcony with outdoor seating overlooking a quiet backstreet lined with trees. Bedding was very comfortable, heater worked great, there's hot water in the kitchen faucet, and since there were only the two of us, there were ample space to open our luggage and spread out. Multiple connector (not adapter) cables were provided, pocket WIFI performed admirably from Tokyo all the way to Hiroshima and the hosting team was very responsive.
The Bad: it's next to a busy road with a flyover with construction happening just next door. This is explained in the listing and the team helpfully provided earplugs for guests to use. However, you can hear not just construction and sirens (which passes quite frequently during our stay) but basically everything that passes through the road below, especially speeding motorcycles. Light sleepers or people with sensitive hearing will have a trying time here without ear plugs or any other kind of sound blockers. Hot water was mercurial during our stay; sometimes would stay lukewarm for a long time although we didn't fiddle with the controls. Also the check-in process wasn't as seamless as the ipad was broken the entire 14 days we were there, even though we have communicated to the team that we and an even earlier guest experienced this error during check-in.
Overall a great stay if you plan to be outside a lot during the day (where most of the noise happens).