I transmigrated into Demon Slayer, but I couldn't even learn the most basic Breathing Style.
I had the weakest grip, poor lung capacity, and shaky hands when holding a sword. One "Next" from a Demon Slayer Corps examiner sent me straight to the support unit, the Kakushi.
Everyone said I was useless, and even I believed it.
Then I saved three lives from a demon's jaws with my first smoke bomb, made from lime powder and Wisteria poison.
I improved Wisteria poison, developed a regeneration inhibitor, designed traps made of Sunlight Ore, and built arrays of ultraviolet lamps...
While the Hashira were still risking their lives in sword fights with the Upper Ranks, I was using science to send the Twelve Kizuki to their graves one by one.
Muzan sent an Upper Rank to hunt me down, and I turned all his lackeys into experimental data.
In the final battle, Muzan asked me, "What are you, exactly?"
I wiped my glasses. "Just an ordinary person who can't even learn a Breathing Style. But science is my Sun Breathing."
