You see that where you are wrong, from what you just commented it's very clear that you don't understand vanitas' character at all, he says and does many things that are contradictory this is bc he isn't sure of himself, and through the dialogue of the story its shown that vanitas does not know himself as much as he thinks, even as child he doesn't realize how kind hearted and selfless he is but jeanne is one of the characters that noticed that vanitas is a actually a kind person, and their love imo didn't happen abruptly bc their are so many scenes where you see vanitas falling for her at first it was obviously an attraction to her looks but it developed from their. That whole chapter with him talking to roland about his feelings for jeanne literally says it all, we have mostly been seeing from jeanne point of view or 3rd person whenever they interact but that chapter shows what vanitas was feeling in all those situations, y'all need to pay attention before u start trashing a story （￣へ￣）
Are you the author to say someone does not understand a book? There is as many way to understand a story as there is a reader so please respect at least that.
Am I the only one that think there is no alchemy between Vanitas and Jeanne? This romance is like happening juste like that. I came here for some angst and good plot. And I am facing with a childish love story... it feels like Mochizuki sensei wanted to lighten her story and find only that fake romance to do so. Instead of such romance, I would prefer fun and short fighting moment with Ronald, Olivier and so on to lighten the plot. Vanitas and Jeanne are not a good couple, de just met her, have some background and her story. As for Vanitas, main character, there is no background at all yet. So hiw van we relate to him gaming in love.... he sais i hate vampire, humains... but BAM he is in love? What???? I feel no alchemy and their story stars as fuck... it is like "they have to fall in love as Vanitas promise to kill her if she goes crazy. And she will, so it will be SO SAD if they are In love when it finally happens!"