>>516163I don't follow or care about this manga, so it might not be accurate, but: the writer decided, seemingly at random and with no foreshadowing, to kill off that manga's main character. Even though the manga is named after that character. No payoff, no meaning, just a random death.
To add insult to injury, a new character with the same name shows up and gradually replaces the previous character's role, right down to hooking up with the same boyfriend.