I found this to be the perfect place for a solo traveler on a budget. I really enjoyed my stay in Kokubunji. It is away from busy Tokyo, yet everything is within reach thanks to the Chuo line. The apartment is really close to the station as well.
The apartment was clean, as described and had all the amenities you'd need. A relatively large kitchen and bathroom for Tokyo's standards and this price range too.
Kokubunji itself is a lovely place and very convenient. Large shopping mall in the station, supermarkets and plenty of places to eat. Friendly and social people too. Good place to mingle with the locals in one of the many izakaya's.
I can recommend this place and would book again without hesitating.