sometime in their school years, harry and draco get into a vicious argument that ends in bloody fists and a month long detention from mcgonagall. harry realizes he's just so incredibly tired from having to fight off voldemort AND uphold his feud with draco so he decides to put an end to it by making amends and striking up a truce (friendship) with draco.
when asking for tips on how to go along with it from his close friends, knowing it will be difficult to get close to draco, they suggest that he go about it in the pureblood manner of "offering friendship," a lengthy ritual that's sure to work on someone as uptight as malfoy.
as per hermione's instructions, harry finds the book on the subject in the hogwarts library and proceeds to start the process on malfoy except the book has been charmed, by a previous reader so that it's not "the magical guide to compliant camaraderie" but rather "to woo a wizard: the beginner's lessons on courting."
instead, draco finds himself as the recipient of an ancient courting method and is just baffled at it all thinking it's a prank but slowly starts opening up to the idea of it while harry is following the instructions with the end goal being draco's friend, not realizing he's given hope to an already hopeless romantic who's been pining after him for way too long.
