This is such a cute isekai manga! The first chapter is a bit confusing while the story is established, but once it's set up it's very interesting. It starts out with Mystia Aren, the daughter of a noble family, at the opening ceremony on her first day of high school in an otome game setting world, then the rest of the volume goes back to when the main character first wakes up as 10 year old Mystia after dying saving someone on our real world.

She's played this dating sim before, and Mystia is actually the evil rival of the main character - who had a very bad ending! So Mystia is determined to change the course of the game and set herself - and everyone else - up for a better outcome in 5 years time when the game's high school setting rolls around.

It's hard to reconcile the bold and selfless Mystia with the villainous deeds attributed to the game Mystia, and the Mystia in the storyline seems to be an amalgamation of the isekai heroine's personality and the personality of the character whose body/memories she woke up with. It's a really intriguing dynamic and I can't wait to read more!