Great communication with the host - we had no trouble at all with the given instructions and the replies came extremely fast.
The apartment is very cosy and clean, a little small for three people but we managed somehow ;) The only disadvantage for some may be a steep staircase leading to the hostel but for youngsters it shouldn't be a challenge to climb it even with heavy luggage. You can find all the necessities here: towels, additional bedding, a vacuum cleaner, an iron, shampoo & conditioner, soap, toilet paper, detergents, dishes and basic kitchen utensils, a kettle, a hairdryer even. WiFi here works pretty well and we were also provided with a mobile WiFi for only 600 yen per day. The apartment also has an AC/DC unit that's very useful ;) Daitabashi station is only a 5 minute walk from the apartment and if you take the Keio line it's 2 stops away from Shinjuku. There are quite a few great shops closeby, we mostly did our groceries in Keio & Lawson.
There's also a coin laundry just around the corner. The area is safe and quiet even though it's the center of Tokyo.
I would highly recommend this place to anyone who wants to travel on a budget but still expects a higher standard of accomodation :)