Shiho's place is a charming house located in a charming, quiet neighborhood—and it's only 5-minute walk away from the Naka-Itabashi station, four stations away from Ikebukuro on the Tobu-Tojo line. It's not exactly in the heart of Tokyo, but I'd suggest choosing a place in the suburb that's close to the station (like Shiho's) over one in the city that's farther from the station.
Along the way to the station you will pass a small bridge with sakura trees planted alongside the river. For more than a week during our stay we almost never encountered other foreigners (and it was a pretty busy season), so if you want to get a feel of local life this is just the right place. I'd suggest to try having breakfast or lunch at Tamago no Tsuruta, a quaint little dinner located just before the bridge which serves Japanese-style omelette, quiche, and lasagna platter with decent coffee. There's also a small Book-Off store branch, across the station where you can get secondhand books, films, music, gadgets, games, even consoles—which is a paradise if you speak/read Japanese (go to its larger branch like the one in Ikebukuro if you're looking for artbooks).
Shiho speaks perfect English so that's very helpful, but other than that she's also very insightful and you shouldn't hesitate about discussing your itinerary with her as she might have interesting suggestions to add to your plan. All-in-all, you will enjoy your stay in her place!