Aiko's parents were murdered by an unknown creature when he was just five years old. Dr. Han, Aiko's parents' best friend was present that day and with him was his only daughter, Yuna. Few saw the creature standing in front of Akio before dematerialize and absorbed by Akio's body. Sadly that was the first time Yuna and Akio meet, upon touching Akio's hand Yuna knew right away they were bonded by a strong font of energy. From that point on she swore to protect and never leave Akio alone.