After being stabbed to death by a patient in the real world, psychologist Lin Ke transmigrates into the body of Nana Komatsu, an inconspicuous student at Teitan High School in the world of Detective Conan. She inherits the original owner's identity but harbors the soul of a profiler and a passion for writing suspense novels—she always applies peelable red nail polish when writing, a ritual that gets her into the zone.

In this world rife with murders, the naturally aloof and trouble-averse girl only wants to "play dumb" and eke out a living, but she can't escape Conan's relentless attacks. Shinichi Kudo (Conan) unexpectedly discovers that this classmate is actually "Mo Tong," the mystery novel author he follows, whose precise analysis of criminal psychology complements his logical reasoning in a wonderful way.

From being forced to cooperate in solving cases to becoming intellectual confidants, she uses micro-expressions and behavioral profiling to crack mysteries, while he uses on-site evidence chains to refine the logic. Her red fingernails are her trademark, and also their unspoken code. As Shinichi succumbs to their intellectual resonance, and as Ran's waiting drifts further and further away from his world, this bond that began with the case will ultimately rewrite everyone's fate—after all, the one who understands a detective best is never the waiting angel, but the profiler who can see into their soul.