Maruzen Nihombashi main opened September 14th.

A large, finely classified foreign section and a small reference library is on
the 4th floor.

Marunouchi OAZO is visible to the northwest of JR Tokyo Marunouchi North Exit. 
The complex has an entrance on the north side, near Subway Otemachi Exit
B2b.  Tozai Line is convenient, but other platforms are quite far.  In
either case stay underground until you find B2.  With the Marunouchi Line, use
Tokyo, not Otemachi.  Various routes are possible between the Jimbocho area and
Marunouchi OAZO but no subway/JR line is convenient to both.

Open 9:00-21:00.  Reference library open 10:00-19:00.

For contact numbers visit:
http://www.maruzen.co.jp/home/tenpo/maruhon.html (J text)

Underground passage map:
http://www.oazo.jp/04_access/pdf/map_underground.pdf (J text PDF)

http://www.oazo.jp/04_access/pdf/map_underground.pdf