The "Egg" metaphor is central. In the lore constructed by the anonymous producer (known only as witCHuus ), the "Custum Tamago" is a digital egg—a vessel for a consciousness that cannot exist in the real world. Early versions of the track were lo-fi, almost abrasive: 8-bit drums, distorted vocals from the vocal synth Utau (specifically the voicebank Teto Kasane ), and lyrics that spoke of molding and breaking .
Based on naming conventions in the doujin (independent) music and rhythm game scenes, this is almost certainly a song from the series (often romanized as Custom Tamago ) by the artist Umaru-chan / witCHuus (also stylized as witCHuuS). Custum Tamago -Final- -witCHuus-
And yet, within that cracked digital shell, you will find something rare in modern music: authenticity . The raw, unfiltered scream of a creator watching their creation fall apart. The "Egg" metaphor is central