
Quick answer — Kōji Wada performed 4 anime themes, including "Butter-Fly" from Digimon: Digital Monsters, "FIRE!!" from Digimon Frontier, "Innocent ~Mujaki na Mama de~" from Digimon Frontier.
Kōji Wada performed the anime theme songs "Butter-Fly" (Digimon: Digital Monsters), "FIRE!!" (Digimon Frontier), "Innocent ~Mujaki na Mama de~" (Digimon Frontier), "The Biggest Dreamer" (Digimon Tamers).
Kōji Wada's first listed anime theme is "Butter-Fly", the opening of Digimon: Digital Monsters.