Pros
Very close to Yoyogi station (few mins walk) with several good breakfast cafes nearby. Also has local restaurants just around the corner. 10 min walk to Shinjuku.
Cons
Very small (as per description) - space for two single beds plus about 1m wide gap for a small table and chairs. Small area outside bedroom with kitchen and hallway.
Some noise from emergency vehicle sirens occasionally, but not loud and would only be an issue if you are particularly noise sensitive.