Nachi Igarashi, a human male with brown hair, appears in the official "Compiler" media alongside his brother Toshi Igarashi. The brothers share a residence that becomes home to Compiler and Assembler, two interdimensional entities. These entities abandoned their mission to conquer Earth upon discovering water's damaging effect on their electronic systems. A tentative relationship develops between Nachi and Compiler, marked by mutual yet unacknowledged feelings, paralleling a similar dynamic between Toshi and Assembler.

The entities' defection prompts their senders to deploy assassins, Bios and Directory, tasked with eliminating the traitors and resuming the invasion. This action draws Nachi into ensuing conflicts and misadventures. The original "Compiler" manga, featuring Nachi, comprises 27 chapters across 3 volumes published between March 24, 1990, and August 25, 1992. New manga chapters were announced for spring 2021, referencing the "goddess of destruction’s return," but without specifics on Nachi's role. Information about Nachi Igarashi remains confined to this original narrative framework.