shoujo or josei mangas that has to do with the supernatural or fantasy where in the enemy falls in love with the main character who happens to be their main target instead of carrying out their missing of killing them. any mangas basically where the main character changed their mind of killing the other main character because of falling in love.
Immortal Rain fits absolutely perfectly. It is josei. The art style starts out a little awkward, but I swear this series is worth sticking with, and the art improves. It has an absolutely amazing story.