Why do the Japanese Police go after non-Japanese?

'Cause if they mess with Japanese school girls, they will get a can of whup ass opened on them:

A pair of patrolmen were attacked that day — by three teenage girls. It started when one of the officers admonished two of the girls for riding double on a bicycle.

But the females were in no mood for complying. One shoved the cop, prodding him in the chest, screaming, "There's nothing you can do about it!" Then her friend kicked him in the leg. As the other cop collared the girls, a third girl arrived at the scene and spat in his face.

A few months ago a young teenage boy and girl were riding double on their bicycle in front of the police box near my apartment. A law enforcement professional who had been inside sitting on his already chair-shaped buttocks sprang into action! Leaping out of his box he yelled, "Don't ride double!"

The young couple replied "OK" and slowed for a few yards, then returned to normal speed and completely ignoring Dirty Harry continued to wobble down the street riding double. Tokyo's Finest slunk back into his box without a whimper.

I thought this was the usual dereliction of duty until I read this article. Now I understand that he feared for his safety and perhaps had a sudden attack of Abe-itis---bowel trouble.

(Need I say it? Nobody was speaking English---it's my translation into what likely be said in English in this situation. It is not a literal translation.)

10:49pm: I had to correct the title as I forgot to write "police" in it.