Imperial CEO Sweet Sweet Love - Chapter 1857

The heavenly God of Warriors was betrayed by his true love and murdered at the very first night of wedding just because his merits made the monarch insecure. Reborn in a hundred years, Nie Tian would be an appendage no more. Reach the welkin, reverse the fate, reign over the heaven and reconstruct the worlds.

- Description from novelupdates

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!?

For unknown reasons, he finds himself transported to a parallel world's Japan, unexpectedly taking over the body of a soon-to-be high school student who had died accidentally. Surprisingly, he did not inherit any memories. However, the first challenge he faces upon arriving here is a language barrier...Just as he struggles to communicate with his new family, a heavenly voice arrives: the black technology system has been activated, and the initial item—translation konjac—has been distributed.This is the story of someone with above-average intelligence but almost no physical strength in the Classroom of the Supreme Power.

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.