We lived in Tokyo for over a year at Tokyo Metropolitan University on the same line as Hatsudai (Keio, Hashimoto). Hatsudai station is a short walk from the house (@ Tokyo Opera City) and one stop to Shinjuku Station (get anywhere from there). We walked sooo much, so the comfortable kitchen and local shops and markets made a good home cooked breakfast a good part of the day saving yen and warming our bellies. We went in winter because we like metropolis travel better than when it is hot and sticky out. At the end of esch day a shower then a soak in the self-heating deep tub was great. The laundry was high capaciy (no need to over pack). The house was well heated and with AC, including our late-teen's private space on the third floor. The house is in a great spot in the middle of Tokyo and strangely quiet when we were resting. We lived well during our stay, the heater under the lounge table was used well while streaming on our laptops and phones. The pocket wifi provided by Rumika was a lifesaver while navigating Tokyo. An international ATM at the 7-eleven 100 meters away gave great exchange rates.
We never met Rumika (there is something to be said for being left to it)but help was always at hand with suggestions and online communications and responses to requests.
We will stay here again and again as our base to explore Japan. Our son is planning a trip with friends with Rumika's cool place as their base. There is a great little bike shop on the walk to Shinjuku station and I will be buying one next trip.
Have fun and treat the place and neighbours with respect and you shouldn't have any worries.
Luke