Or something else...
A few days ago, Youtube recommended me this video of a Japanese siren doing it's musical test:
https://www.youtube.com/watch?v=Aia6ncq8W64
The siren kinda resembles an i-Force, but the way that it's mounted makes it look like a Quadren. It's not the first time we've seen foreign sirens in Japan, like the ATI's at a military base.
I also got the location of the siren, along with best-I-can-do street views: 34.17399271861564, 131.4735968740705
https://www.google.com/maps/@34.1735925 ... ?entry=ttu
https://www.google.com/maps/@34.1745514 ... ?entry=ttu