XBlaze Code: Embryo is a visual novel adventure game that tells the story about the events that took place about 150 years before the BlazBlue fighting game. The protagonist of the game is Touya Kagari, a sophomore of a Hakou North Academy. One day, he ventured where he shouldn't and came upon a wounded man who instead of thanking him for his assistance and concern attacked him. A mysterious girl came to Touya's aid and saved him. Thus started the new chapter in Touya's life he had no idea he was a part of.

Unlike the bulk of visual novels that consist of reading with occasional choices that branch the story, this game features TOi (aka Technology of Interest) which automatically gathers articles for Touya where player can decide which articles to read and which to neglect. By reading articles, certain events will become available, which will change the course of the story.