What would the police have done if they had seen his noose in the boot of the vehicle?
Would they have arrested him for trying to an hero, or would they just nonchalantly tell him to get some therapy before taking the noose away and leaving?
After leaving this comment I had to look it up. Japanese GKT (gatekeeper trainings) for suicide prevention varies wildly from prefecture to prefecture, with some being a basic 1-2 hour class presentation on mental health while others are more multimodal programs. A lot of GKT were also provided by third part local councils rather than a set standard.
In short, my guess is as good as any lol
You can learn more (or rather, learn why you can't learn more) about it
here
I can't expect every officer to be a chotto matte man