MTL - Midnight Cinderella - Chapter 20 Week 20

Tang Dynasty：Live with princess Changele, Li Er is going crazyAfter Xiao Ran woke up, he find that half of his bedroom had gone through time and space.Next to him is a girl with exquisite features and a beautiful appearance. The girl is actually Li Lizhi, Princess Changle of the Tang Dynasty.In the seventh year of Zhenguan era(a era of Tang Dynasty), thermal underwear, baby warmers, and hot water bottles have become the best-selling products in Chang’an City.This year’s Chang’an City was very cold…Xiao Ran made a lot of money!Relying on Blue Star’s various technologies, Xiao Ran successfully captured Princess Changle’s heart and prevented her from marrying Changsun Chong.The purification of fine salt, sugar, medicinal materials, and potatoes and sweet potatoes all entered Datang one by one.

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

When The Cute Kunoichis Spied on Their Teacher's Secret is a light novel written by Kazuma Kamachi and illustrated by Ryuushi Tajima.

The story takes place in a world where Japan never ended their isolationist phase, and agents from foreign powers are always threatening to steal the country's advanced technology. In order to combat this threat there has been a resurgence of ninjas that use Strategic Martial Arts, techniques that combine cutting-edge modern technology with a traditional foundation of martial arts and ninjutsu. The story follows Souha Sugiyado, a 17-year old ninja instructor and former ninja prodigy who was forced to retire from active duty by the wounds he suffered in his last mission. Souha's four students are all kunoichi who have all gained the rank of Elite Ninja, the highest official rank available to ninja. However, one day two Shogunate ninja approach him with the news that his four students have gone rogue and have stolen a portable modular nuclear reactor, and thus they ask for his help in bringing his students to justice.

Yin BiYue has made the worst purchase ever. After transmigrating countless times into the bodies of canon fodder villains, he buys a ‘Fiend Halo’ from the Rebirth Company, supposedly the best aid for an up and coming final BOSS!

He’s ecstatic to finally get a villainous role where he won’t die after just a few lines, if any at all, and is raring to become the best opponent a protagonist will have… However, why was everyone looking at him with pitying eyes? Why was the protagonist rushing over to help him get out of his crimes? Most importantly, why was his ‘Fiend Halo’ just making things worse?!

Meanwhile, the intern salesperson at the Rebirth Company discovers that he might have accidentally sold a prototype White Lotus Halo to a certain villain…

- Description from Novelupdates