Toaru Majutsu no Index - Volume 13, Chapter 10: Their respective battlefields. The_Way_of_Light_and_Darkness.

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

I just lost myself in the deep and shallow temptation of her.
——by Jiang Hanyu
Everyone knows that the person Nan Gao doesn’t mess with is Jiang Hanyu
She is arrogant and fierce, relying on beauty, a proper little overlord in school
Everyone thinks that the best relationship with Jiang Hanyu is to call him brothers.
But one day, someone found that Jiang Hanyu was holding the hand of the goddess of coldness in the class and lowered his eyebrows after class.
Unruly girls become gentle and charming
He also said in an unbearable and irresistible voice, “Si Nian, will you give me a kiss?”
Then everyone knew that the best relationship with Jiang Hanyu was…

TIPS:
1. The Great Demon King X Miss Gao Leng
2. Campus text

- Description from novelbuddy

If you just stay still, you’ll get to the middle.If you try to show off how good you are at work, the tasks will only increase.By the time I realized that the absolute rule of the military also applied to the position of the crown prince, it was already too late.

I fell into a wannabe murim.But apparently martial arts is supposed to be difficult?Hm… Is it really that bad?