Tatsuya is a childhood friend of Wakaba's. When they were little, she recruited him as her "Onion Prince" to protect her from the taunts of her classmates. As he's grown older, he's come to regard Wakaba with affection, but she has since turned her attentions to her new "Prince", Saionji. Tatsuya is the only character who goes through Mikage's confessional and is rejected as a duelist because his heart is "too pure" to be converted.