My dudgeon is reserved for the Effete-police; their Inexcusable inaction:
This disturbed-guy WROTE-them a letter, detailing /When, on the shifts he would strike /Why he would strike /Where! he would strike.
[In the event: the exact date-only was missing.]
I cannot imagine a more justifiable nay, Unarguable action--on receipt--than taking this man to (whatever psych-folk are deemed Professionals there).
Releasing him after any "little chat" could only be called: dereliction of the Duty of Police {everywhere}.
Shall follow up (unless streets are afire here, natch; ya never can Tell, hour-to-hour) and see if the Japanese governance is generally as out-of-touch with 2019? or there was just a rilly-Dumb local force.
These folk were Artists, 'un-Japanese? humanitarians in that their pay, coverage of their workers was unlike the slave-conditions of their competitors.. described. :-/
Ed: oTpy