The buildings of this site are numbered, like a traditional danchi, but the buildings are now owned by the 気象庁 Japan Meteorological Agency (JMA), which has a research center just down the street (map).
The northern of the two sites is 清瀬住宅 [Kiyose jutaku housing], and shows up on a repairs list on the JMA’s website. The southern site is labelled 気象衛星センター中清戸宿舎Ⅱ [Meteorological Satellite Center Nakakiyoto quarters II].
I can’t be certain, but it appears that the sites for these buildings used to be radio or tv towers (in the photo from 1974/78, below left, the cross-like mark in the middle of the light fields may be the guy-wires of the towers).
Building 141-1 of the northern site, Kiyose jutaku housing 清瀬住宅:
Faded map from the north portion (it is the left-half of the board):
The southern site: 気象衛星センター中清戸宿舎Ⅱ :
Obscured diagram of the Meteorological Satellite Center Nakakiyoto quarters II: