Stayed at the place for 10 days.
Fantastic location, close to both Otsuka and Ikebukuro station. This made it super convenient to travel by JR line (to Shinjuku/Shibuya/etc.). There are also many delicious places to eat near the stations.
The neighborhood is quiet with the occasional loud siren sound/loud cars, but it didn't bother me much.
The room itself is located on the 5th floor. It is quite a hassle to get to, especially with heavy luggage, since there is no elevator. But that is only when you are checking in/out.
The room is clean with everything you would need.
The host was super helpful with everything and very punctual with replies through Airbnb messenger. The pocket wifi inclusion was also very helpful.
One thing to note, the wifi signal, as fast as it is, is not very powerful. Especially around the bedside area of the room.
Overall would 100% stay there again if I were to come back to Japan anytime soon!