Reincarnated Princess Wishes To Avoid Death - Chapter 8

After going bankrupt, Cheng Jinzhi woke up and found Rong Si, her nemesis, lying beside her.
When Rong Si kissed her, she realized that she had returned to twenty years ago, when Rong Si was still a pauper with a lot of debts.
This article is also called “How to Sleep the Winner of Life?” “” Queen, I think your thighs are missing me”

Content tags: entertainment circle, rebirth, happy friends, sweet text
Protagonist: Cheng Jinzhi, Rong Si ┃ Supporting roles: Xia You, Gou Yu, Fu Xinbai, Fu Qiansheng

- Description from novelbuddy

Based on the popular Vocaloid series, by HoneyWorks, called “Kokuhoku Yokou Renshuu (Confession Rehearsal)“:

Natsuki, a third-year at Sakuragaoka High School, who holds unrequited feelings for her childhood friend, Yuu, who’s in the Film Club. However, instead of being honest about her feelings, she makes him be her confession “rehearsal” partner. Unable to say her true feelings, things start to get complicated when Miou and Akari, who are also in the Art Club, get involved! Will she ever be able to confess for real!?

A gigantic mouth appeared in the sky and swallowed the entire Earth, scattering the shattered fragments everywhere.“Welcome to the Myriad Heavenly Hunting Grounds, your talent is the Lord's Cottage.”Earthlings received the developmental ability called Lord's Cottage, beginning their struggle for survival in the Myriad Heavenly Hunting Grounds.Fang Jie, holding the initial item 'Faction Conversion Command', gently tapped on the undead faction. Starting with the undead fission talent, he could make his subordinate undead split and increase in value, and the talent could also be upgraded.

Long Fei, a cross-timer and doujin, is an otaku who traveled to another world. In the original world, he was an otaku fan of Gundam and military science fiction.

He died in an accident and was reincarnated into another world. The Gundam works he had read before his death and the techniques in various military novels could be brought to another world.

How would he use the Gundam that Long Fei created? What waves can be caused in this different world?