Choji belongs to the enigmatic race of Nerra, a scion of Elder Evils born from some ancient powers beyond mortals' knowledge. The nerra are commonly known among planar scholars as "mirror entities." When every humanoid creature is born, a nerra is born as its reflection.

There are multiple types of Nerra, each with unique abilities that reflect the person they originate from. Some have mastery over illusion magic, some over shapeshifting, some over their shard weapons, and so on. 

There are rumors of the Nerra kidnapping people into the Realm of Reflection that exists behind every reflective surface; sometimes they disguise themselves as important political leaders to begin or end wars, and some even blame the Nerra when a civilization becomes ruins. However, the purpose of the Nerra race is unclear, but since they closely resemble the Elder Evils, most mages believe they are a threat to mortal lives.

Choji is a strange Nerra. He yearns to lead his own life, not merely existing as someone else's reflection. He left the Constellation of Eyes and the Nerra's quasi-hivemind to find himself in the city at the center of the multiverse, Sigil. There, in the bronze torus city above the tallest peak of all realms, he was adopted by Lord Estavan, one of the most powerful merchants who has his trading routes spanning all over the known multiverse. Lord Estavan found the lost Nerra, took it under his care, named it, and gave it the role of his son to serve him.

The Diamond Record is written in the Nerran language, a language of light invisible to a humanoid's eyes. It details Choji's journey under Lord Estavan's direction and his turmoils within.