I'm Not Tokisaki Kurumi

Who is Tokisaki Kurumi? She can turn back time and defy fate to rewrite her destiny, or split into clones and gang up on Mana.

Long black hair, plenty of sex appeal, a school uniform, and a harem king for an era: Itsuka Shido, blushing bright red after she flirts with him.

Everything above is complete nonsense. This is a story with a female protagonist, not a gender-swap story, and it has a yuri direction (though the tropes should be closer to a gender-swap yuri story). No yuri harem, and the pairing is clear.