Here are the pros of Masami's apartment: relatively spacious by Japanese standards, clean, nice leather couches, comfortable beds, quiet neighborhood, a nice restaurant street nearby (we recommend Mexipon and the Italian place), a hip coffee shop called Paddlers ten minutes' walk away where you can get breakfast muffins as well, quick access to train line, fascinating walks possible in the neighborhood from the train station to Yoyogi Park, and an escape from the frenetic atmosphere of Shinjuku and Shibuya.
The cons: the apartment is utilitarian rather than stylish, checkout time is an absurdly early 10 am, the 10:00 am checkout time translates to difficulty storing luggage in Shinjuku as all the lockers are taken. Since check-in is after 4:00 pm, does it Really require Six hours to clean the place??? Masami should follow hotel standards with a 12:00 noon checkout.
NOTE: It takes several minutes for heat to come out of the AC units, just be patient.