A little secret and fun from the creators.
Proper 6 stone correct bulding now.

Use spectral vision

1 - Matsumi Shrine look for corrupted apartment.
2 - Forest Kirigaoka Shrine
3 - Corrupted Apartment Block Shiratsuki Shrine
4 - Shibuya underground first time separated with KK.
5 - Rooftop of the Middle School Bulding
6 - Shibuya Crossing top high mall bulding roof.

Blue Stone Room is located in Middle School 3 Floor behind Nurikabe yokai
After collecting all six stones should be placed there :)

Locations