I was Caught up in a Hero Summoning, but that World is at Peace (WN) - Chapter 1484 - Intermission: Other Immigrants around that time

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!?

Gu Yuanyaun had transmigrated inside a currently popular novel. She transmigrated into the body of a woman that carried the same name as her. Coincidentally, the woman already had four sons but was forcibly separated from them by an accident and ended up with a miserable ending.

As time gradually passed by, it was always accompanied by change. The four sons grew up and became successful individuals. They became the bosses on their own chosen fields while on the contrary, their mother, Gu Yuanyuan, instead turned into a teenager which was even younger than her sons.

Seeing that the hurdle was too high, Gu Yuanyuan, who became a pea princess on the story, decided to find her four sons.

The eldest son was a billionaire.

The second son was a legendary medical doctor.

The third son was a martial arts prodigy.

And lastly, the fourth son was a genius professor.

Gu Yuanyuan smiled with a kind face and said: “Dabao, Erbao, Sanbao, and Xiaobao. I’m your mother”

Looking at their mother’s appearance that could be mistaken as their own daughter’s, the four big sons was: “…???…”

- Description from Novelupdates

Rise Lee, a well-known A-rank esper in the federation. He was even ranked as one of the strongest among the A-ranks and recognized as one of the hopes for humanity. However, he wasn't only famous because of his prowess or his attractive appearance; Rise was more infamous because of his terrible personality. He was called a villain by most guides and espers for a reason.And who would guess that Rise Lee was really a villain, in a literal sense? The terrible truth then unfolded to him. He, Rise Lee, is one of the main villains of the novel. Rise Lee spat out a mouthful of curses and swore that if he had a second chance, he would mess up this damn novel until everyone went down with him. If the author was in front of him, he too would be destroyed with him! And a second chance did come! Rise Lee, the villain, woke up five years before the main storyline! Heh. So what if he was a villain destined to die? That protagonist who killed him, and the author... He would screw them over. Being a villain, be damned. In this rebirth, he would take and mess up everything. What did you say? The protagonist’s love life? Heh. That too. Rise would take his lover. The male lead... will be his.

Humanity was on the brink of destruction. Muyoung, an assassin from the Forest of Death, fell to his knees. There were corpses all around him. For years, he had worked for the Forest of Death and had finally been able to eradicate them. Now, he, himself, was about to die. He closed his eyes as he felt his heart stop beating.