The apartment is well located, close to subway and really not so far from Shinjuku. You have also a direct bus to Shibuya, only 210円 wich is really convenient !! Close from convenient store, supermarket and restaurants, you can also enjoy the calm of the neighbourhood.
The apartment is a little small but way enough if you're by yourself.
Seagull was really easy to contact and answers very quickly so don't hesitate to contact him if needed.
I also enjoyed the thoughtful welcoming writing board with origami at the entrance.
I stayed a week there, and spent a wonderful time. Totally recommend !!!