MTL - Cult of the Sacred Runes - Chapter 581 Trial tower

Intellectual Villages are old fashioned rural villages recreated with cutting edge technology. Those villages attract the Japanese monsters known as Youkai.

The high school boy Jinnai Shinobu lives in one of those villages and has a Zashiki Warashi living in his house. He tends to run across Youkai with unnerving frequency and this often leads to trouble for him.

After dying from a strange terminal illness, Ling Lan was reborn into a world 10,000 years into the future. Although she dearly wished she could just live a peaceful and uneventful life in her new healthy body, fate had other plans…

Forced to disguise herself as a boy just so she could inherit her deceased father’s premium military benefits, Ling Lan’s journey to adulthood was full of challenges. After much difficulty, she finally turned sixteen when she could drop the charade. But before she could grasp her newfound freedom to get married and start her own family, a twist of fate results in her being thrown into the Federation’s top military boys’ school.

With these twists of fate, Ling Lan had little choice but to walk further and further down a path of no return, one of cold and aloof dominance…

- Description from Novelupdates

To treat her sick brother, she was forced to marry him in place of her cousin, who was disfigured and paralyzed. At first, their relationship was purely transactional, with neither caring much for the other. But after going through a lot together, they fell in love with each other. He doted on her deeply.She was considered an ordinary person by the world, but it was later discovered that she had multiple identities - a mysterious underground boxing champion, a highly-skilled doctor, and a mysterious and renowned composer... He also realized that their fates had been intertwined long before they met.

There’s a legendary Bishoujo Game that has become popular among Japanese gentlemen.