That Time My Kohai Reincarnated With Me as a Slime
Yuta Tamura was an ordinary office worker in modern Japan—overtime every day, no dreams left, living only to work until his body gave out. His life ended abruptly one night after leaving the office, struck by a speeding truck.
Death, however, was not the end.
Tamura awakened in a world he knew far too well: That Time I Got Reincarnated as a Slime. More shocking was the fact that he had reincarnated as Tamura, the junior coworker (kohai) of Mikami Satoru. Retaining all memories of his past life—and possessing deep knowledge of Tensura from repeatedly reading the web novel, light novel, and watching the anime—Tamura was ecstatic. Of all worlds, this was his favorite fantasy.
He believed his new life had already peaked.
Then fate struck again.
While Tamura was still overwhelmed, the original tragedy occurred. Mikami Satoru was stabbed. Tamura, standing beside him, was stabbed as well. Both died together—and both reincarnated once more, this time into the Cardinal World.
Inside the same cave, at the same moment, they were reborn as the same species: slimes.
Mikami Satoru became Rimuru Tempest, following the familiar path of the original story. Tamura was reborn alongside him—but unlike Rimuru, Tamura carried something that did not belong to this world.
[A Sign-In System.]
Every day, without exception, Tamura received a reward. The rewards varied wildly: Extra Skills, Unique Skills, Ultimate Skills, racial evolutions, rare bloodlines—but also non-combat abilities such as cooking, research, business management, politics, strategy, and diplomacy. Some rewards seemed trivial at first. Others were absurdly powerful.
The result was simple and absolute:
from the beginning of the story to its very end, Tamura was always stronger than Rimuru.
Yet Tamura had no desire to rule, conquer, or shoulder the fate of the world.
In his previous life, he had been a corporate slave who worked until death. In this world, he made a single decision—he would live freely and enjoy life. While Rimuru followed his destined role of building a nation, negotiating with Demon Lords, and standing at the center of history, Tamura stayed in the background. He intervened only at critical moments, often reluctantly, casually, or with blatant laziness—despite his actions repeatedly changing the course of events.
Much of the story revolves around the comedic contrast between the two:
an idealistic senpai burdened by responsibility, and an overpowered kohai who wants nothing more than good food, peace, and a stress-free life.
However, the world does not ignore anomalies.
Tamura’s unnatural growth, his mysterious system, and his easygoing attitude toward overwhelming power begin to draw attention—from monsters, humans, Demon Lords, and even higher existences beyond the known system of the world. At the same time, the system’s unique rewards lead Tamura into multiple romantic relationships, forming a harem that develops naturally through shared experiences, emotional bonds, and irreversible choices—distinct from Rimuru’s path.
This is a story of two men who died together, were reborn together, yet chose entirely different ways to live.
A story about overwhelming power without ambition, fate that refuses to be escaped, and a man who only wants a peaceful life—while the world keeps forcing him to become something more.
