Shot in the city of Hiroo, Tokyo.
When I entered into a shopping mall, I found a hole on the floor. And I could see the downstairs hall through the hole. During I watched, people appeared in the scene sometimes. Everyone passed over the scene in a quickened pace.
A second look confirmed that the floor was decorated with many triangles. And I felt compelled to count how many triangles were drawn on the floor. Soon, I took cognizance it was impossible for me.