After Transmigrating as a Demon, I've Been Adopted by Angels! - Chapter 4

The Student Council President’s Secret Laid Bare (生徒会長のセキ裸ラな秘密) is fairly standard 2D Dream Bunko fare but with an exhibitionism theme.

Basically, it’s about a guy who discovers the student council president is an exhibitionist and gets roped into helping her with that fetish.

Gabriel, a dominant omega, is caught up in a complex web of intrigue and danger at the royal court. After uncovering the truth about Olivier, a member of the royal family, and inciting a rebellion, he is marked by an unknown alpha. As the rebellion overthrows the old order, a new empire emerges, driven by a ruthless ruler whose rise Gabriel inadvertently enabled.Haunted by the weight of his actions, he flees from his family, his past, and the dangerous ties of the court. On the run, Gabriel must deal with shifting alliances, hidden enemies, and the growing power of the mysterious alpha whose mark he carries. As the empire's grip tightens and ghosts from his past resurface, he must decide whether to confront the forces threatening to engulf him—or risk losing himself completely in a world that regards him as either a pawn or a weapon.

“Can a person suffering from amnesia have a total change in personality?”

The question lingers in Feng Ning’s mind.

Other people treat her coldly, claiming she is insidious, cunning and selfish. There were even rumors of her not being a virtuous wife and having illicit affairs with other men. However, she had no such memories.

After waking up from a heavy fall and knocked her head, she is now polite, treats people in good faith, and tries her best to get on her husband’s good side. No matter what she did, the past could not be undone and despite having no memories of it, Feng Ning calmly accepts her fate and slowly tries to mend things back. But why must fate be cruel to her? What did she do in the past to deserve this? In the first place, how did she end up in this sorry state?”

- Description from Novelupdates

Upon meeting the girl who would become her adopted younger sister, the duke’s daughter Christina regained memories of her previous life. Through those memories, she learned that her new sister, Mishuli, was the heroine of a certain story. And though the story depicted a Christina who abused her sister, the real Christina turned into a siscon who spoiled Mishuli to no end.