Racist guy ran into me then followed me!

Yesterday I was walking near my home in Shinjuku on a quiet street, going up a walkway to get to a main street - literally was just one Japanese man in his 40s-50s and myself. The man doesn't give me space, deliberately runs into me (HARD!), and then when I ask him in Japanese why he did that, he starts saying he will call the police, starts following me... it gets better - he starts yelling racist slurs (baka gaijin, etc..) and said I should leave his country. I started filming him when he started following me - unsurprisingly, he left straight away.

What the hell is wrong with people? I was peacefully walking with my earphones on and this pathetic excuse for a person decides to hurt me for no reason.

And today something similar happened - I was walking to my office from Shinjuku station, and someone on their bicycle rides right in front of me, nearly hits me, and had to swerve not to hit me. I was shocked and I said in Japanese "what are you doing" - with my earphones on. I keep walking. Few seconds later, he bikes back to me and yells at me, saying I AM the one who broke the law - even though I was just walking, and he literally almost hit me.

Why is this happening to me non stop? Any suggestions?

I didn't want to waste hours of my time going to the koban because I know they cannot do anything.