 Ryoga is Nanjirou's first child from a previous relationship prior to meeting Ryoma's mom, Rinko.Though they grew up together as kids, Ryoga was forced to separate from Ryoma after Ryoga's aunt from his late mother's side won a custody battle with Nanjirou.It is unknown how old Ryoga actually is since he's apparently not a student, though given the rules of the U-17 camp, he would have to be 15-17.