Shunji is the older brother of Rin Kamishiro. He died for an unknown reason. As Rin's master, later told Kazuki a bit about Rin's past and how he was forced to become cruel to Rin instead of the kind brother when he was named her master. He also told Kazuki that what Rin needs now isn't intense training, but someone to allow her to feel the warmth of friendship, which he deprived Rin of when she was a child. A week later, the duel took place, which went short when Rin's master collapsed due to old age. As his time nears, he apologized for all the harshness he done to Rin as her master, hoped for her forgiveness and bade Rin farewell as he died.