MTL - Self-cultivation of Male Supporting Role - Chapter 309 Glamour

The second prince has come of age. To celebrate the advent of such an occasion, the search for a suitable bride began. My younger sister was expected to go to the Royal Palace as a candidate. However, despite this, she eloped the day before her departure. I, the older sister she left behind, looked almost exactly like her – so much that we were often mistaken for twins…

One month, right? For just one month, shall I substitute in for my sister?

Shi Jin once read a book. It was supposed to be about satisfying the desire for vengeance.

The main character, also named Shi Jin, was the sixth son of his harem-novel-protagonist-like father. All was well—while his father was alive. But after his death, Shi Jin’s five elder half-brothers tormented him, eventually leading to his death. The protagonist was reborn, determined to take revenge, and… the novel was discontinued.

That day, Shi Jin almost spat blood and dropped the book into a shredder. The next day, he died in a car accident. Somehow, when he came to, he had transmigrated into a teenager, a youth also called Shi Jin.

There was only one problem. His father had just died. His older brothers were about to torment him…

Shi Jin: Let’s eliminate my brothers’ hatred, my goal is to keep my life!

- Description from Novelupdates

He was on his way to buy some beer to celebrate his acceptance as a civil servant when he was suddenly isekai’d by truck-kun.

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!?