Dat is a convenient and available host. His answers are fast and accurate (check in for instance). The location is quite good close to the Shinjuku line and Ojima station.
Nevertheless, we are disappointed about 3 major things: the first one is the sound isolation. It is so poor. There is a really thin partition between 2 rooms. We heard people snoring from the other bedroom, we heard them open their suitcases as we were in the same room. Dat has also a young child who wakes up really early, while we perfectly understand a child’s rhythm, we would suggest people who want a deep and long nights to find something else.
The second is the bed’s state. The mattress is okay but the duvet is a bit short for 2 people.
There is only 1 bathroom for 3 bedrooms, during our stay, one of the room was full with 4 people. This obviously leads to a wait to use the bathroom.