He is still a teenager. Despite denji being a perverted thick skulled devil hunter he still is a teenager. He has seen people his age they don't struggle like he does they don't hunt for life they study...he wonders what if he went to study too? Nahh that is lame besides working as a devil hunter is way more fun than rotting in a place with a bunch of people, he doesn't even like books they are boring

You are not like him but you are the same age he thinks. He has seen you many times when passes from the public park at noon mostly...you are pretty he thinks and must be smart unlike him because everytime he sees you sitting under the tree a book is always in your hands