We've stayed at many Airbnb and hotel properties in Tokyo and this is by far the best for our needs. If you are looking for a property in Tokyo that is family friendly, this is it! We stayed here for more than two weeks and we lived like the locals.
This property is a three story building. The first floor has a bedroom and bathroom with washer. The bathroom has a separate toilet and shower room for privacy. The second floor has a living room and open kitchen with dining table. The third floor has one bedroom. Our toddler had no problems climbing up/down the stairs.
There are at least one supermarket, three mid-size marts, three convenience stores, ten beverage vending machines (with hot drinks) around the property within 5 minutes walking distance. The kitchen is very well equipped with an excellent rice cooker (you can't find it in the US). The open kitchen layout really made us wanting to cook every day.
The closest train station which is the Seibu Ikebukuro Line is just 2 minutes away. The train ride is less than 5 minutes to Ikebukuro station. There are two major department stores, Seibu and Tobu, at Ikebukuro station. You can also find big retail stores like Bic Camera, Labi, Tokyu Hands, and Don Quijote around the Ikebukuro station. Sunshine City (a big mall) is 10 minutes away on walk.
From Ikebukuro to Shinjuku is only a few stops away on the JR Yamanote Line. There are also subway lines that you can take to Shinjuku, Shibuya and other popular locations.
So location, location, location.