The whole "Assassin wanting to escape their line of work and go full domestic life" is a bit cliche by now. Either they die trying or succeed and live a happily ever after life and then came the sequel that sees them goes back to their old way.
Its been done again and again and again and again that the only thing that would make it interesting is the twist(like Romeo and Juliet, but with NINJA from the warring period in modern era) the creator put into it, or the worldbuilding and/or background lore the author put into it(taking place on a Strangereal Earth, or outright other planets).
Edit: Lots of American Incels are offended by this and striking me down. Lol. Lmao