Mitsubishi has announced it will redevelop an area in Yurakucho in Tokyo.
The 2 bldgs. in question are just west of the Bic Camera on the west side of the station around 35°40’30.56″ N 139°45’46.21″ E.
http://akihabaranews.com/yurakucho-building-reconstruction-project/
“The statement suggests that many of the specifics remain to be decided, except that the new constructions will become “flagship buildings of Mitsubishi Estate that will lead the restructuring of the area.”