As the one who administrates the Tri-ni-sette, he is the one who gave the Vongola Rings and Mare Rings to Uni's ancestor, Sepira, who in turn entrusted the Vongola Rings to Giotto. For decades, he had selected and tricked seven people in each generation that he considered the strongest through contract job or representative battle and forcefully make them protect the Arcobaleno pacifier, cursing them into babies. After Bermuda's defeat, he appears in front of Tsuna and the others and reveal his true identity as Kawahira. He, along with Uni, are the last two special races that had been existed even far before humans whose job are to protect the Earth through Tri-ni-set. However, their race died one by one until he, and Sepira are the only ones remained. They decided to split the seven stones of Tri-ni-set into Arcobaleno Pacifiers, Vongola Rings, and Mare Rings and gave them to human race as they alone unable to provide enough flames for the rings. He intended to remove the pacifiers from Reborn and the others and cursed those he had selected, however, Talbot arrives and came up with another solution to keep the Tri-ni-set safe. With Uni's assurance of the future of the Tri-ni-set, Kawahira agreed to give up the order of the Tri-ni-set to Bermuda and the Vindice, entrusting them to the future generations, and removes the Arcobaleno curse from Reborn and the others.