Yasuo is one of the Seven Cambions, Human-Digimon hybrids that once were connected with the Seven Great Dark Lords in the past and now in the present, as the Hybrid of one of the Seven Dark Lords he is also ranked among the twenty Ruler Guardians of the Digital World that have defended the Digital world from threats of Good and Bad since time immemorial. In his past life, Yasuo was a Prince of Kingdom invaded by a Tyrant and defended by a Heroic Knight however Yasuo and his sister sacrificed their lives to end the battle, protecting their subjects from the Tyrant Prince's Wrath.