One Piece: Fist of the World - Chapter 25: Pirate Flag

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.

Hero Zhang Han was frustrated in life originally, but he stepped into the Cultivation World by a stroke of luck. Possessing divine natural gifts, he ascended into the disaster-crossing period step by step. He had imagined his life would not have any hardships anymore, but unfortunately incurred the god thunder since he violated the fate. After he woke up, he was surprised to find that he was reborn, going back a few years ago. He found that the world was different from what it used to be after his rebirth and he had a lovely daughter.

She is the slow-witted idiot of the Prime Minister’s Residence. Everyone bullies her. He is the most respected and unfeeling Prince, with frightening ability and absolute envy! Together, they are conferred an imperial edict of marriage.