I wish he is pretty lax teacher

Neither do I, maybe @captain_obvious can explain

It's a reference number for a (very depressing) hentai called Emergence, where a girl gets bullied, addicted to drugs, raped, and many other terrible things. For some reason it has become a meme. (If you've ever seen the image where a girl is looking around her class and has a bunch of nice things written on her desk, I can tell you the original is not nearly as nice.)

Who are you and what did you do with the Captain

Read his name, the answer becomes obvious, even captain obvious could tell you th-... wait a minute