48 Hours a Day - Chapter 60 - The Mannerheim Line Welcomes You II

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

Never should be exposed, just the two of them in their youth.「I’ll be making your meals from now on, Sensei.」I, Reiyu Tenjō, am a high school teacher.When I shared some food with my neighbor, it turned out to be my student, Yuunagi Nishiki. If this fact is discovered, I might be fired from the school?That’s why we signed a 『Neighbor Agreement』 in order to keep our secret.Since we both live alone, the plan was to help each other out when one of us was in trouble——but somehow, I got won over by his cooking.Instead of helping him, I find myself increasingly spoiled and dependent that I can’t live without him anymore.‘No, Reiyu Tenjō. He’s your student, someone you are not supposed to fall in love with!’Drawing closer and then apart——their love sways ambiguously like waves.A youth romantic comedy filled with secrets between a teacher and student begins here.

This is the story of a young slave gladiator in an underground arena. He doesn’t know about his past or how he got to where he is, only that his name is Aegir, and that he is strong.