Hiro secretly trolls these boards as an anon.

He goes to all boards, hiding in the shadows, posting anonymously
You know it's him because of the poor english, the love of anime, and also the air of confidence.

He can change his ID at will, his flag is chosen by a drop-down menu. Sometimes he will sit there and argue with himself for hours, just for shitposting. Entire threads are filled up by Hiro constantly changing ID's. He can do whatever he wants.

Be nice to Hiro when you see him, and you will have nothing to fear
When you meet him, just reply with "good boy Hiro". In his poor english, this is the highest praise you can offer