It's an amazing manga!! Warning: He's not as yandere as others in this sub but he's definitely smitten for her and he's very powerful.
Plot: The protagonist reads a novel about Charlotte, a Hopeless Romantic who chases after the love of Duke Hestia who does not love her back, and her tragic end in the pursuit of love; including her loyal butler lancelot who is in love with her --- who dies at her demise. Saddened at his horrific end, she leaves a comment on the novel about how much she loves him and wakes to find that she is now Charlotte!!
It's very fluffy!! No smut and there's not that much conflict. It's such a breath of fresh air because it breaks a lot of tropes that you find in isekai stories quite a bit.
Spoilers:
• They fall in love together quite quickly
•Lancelot is very strong (I don't know whether he's overpowered but he has a MAJOR skill)
• >!He finds out she's not the real Charlotte quite early on. He loves her regardless though which is quite sweet🥹!<
• >!The ogCharlotte made a contract with a demon and is reincarnated as another character in the story, hence why the protagonist reincarnated in her place!<
• >!Apart from ogCharlotte, there is another character that makes a contract with the demon for something you might not expect!<
• >!Happy ending for everyone, bittersweet ending for ogCharlotte who keeps her love until the very end!<
Would recommend...it's not as heavy as I usually like to read but it is quite a refreshing story from all the cardboard tropes and it's great if you're looking for happiness and whimsy (at least from my point of view, I've only read about a quarter of it)