The ability of the protagonist of any book, movie, tv show, etc. to be able to almost effortlessly overcome any task within a relatively short amount of time.
In the anime Bleach, the soul reaper captains spend centuries mastering their abilities, but Ichigo is able to surpass them in a matter of days through the power of protagonist bullshit.
The Hentai Protagonist Haircut (or hph for short) is that generic haircut dudes get looking like a damn bowl on their head. Literally the most boring possible haircut a dude could get.
Person 1: Hey did you see Dane's recent haircut?
Person 2: No, what does it look like?
Person 1: He's sporting a damn Hentai Protagonist Haircut
Anime Protagonist: *is born with blue hair
Doctor: i'm sorry to say this, but you now have Anime Protagonist Disease
Mother: Do i have to die or him?
Father: why not BOTH?!