Can I ask what makes this game different from other Joseimuke gacha games? (Like Ensemble Stars)

Like, I know the only playable is Nikki.. But I don't know if other characters are treated the same as say, Ensemble Stars characters or Helios Rising Heroes characters.

Apparently in this game, characters can and do die, but I'm wondering why they're able to do that compared to OTHER joseimuke gacha games? I'm very interested in knowing the marketing differences