That trend is because a lot of them start life as “light novels” (similar to young adult novels, have a few scattered pictures and stuff), and those are intentionally titled so you have an idea of what you’ll be reading, because there are a freakin’ lot of them. It’s basically the synopsis blurb, just as part of the title, so you read it while looking for a book rather than going out of your way to know what its about.
That trend is because a lot of them start life as “light novels” (similar to young adult novels, have a few scattered pictures and stuff), and those are intentionally titled so you have an idea of what you’ll be reading, because there are a freakin’ lot of them. It’s basically the synopsis blurb, just as part of the title, so you read it while looking for a book rather than going out of your way to know what its about.