The Inheritance Ceremony is a ceremony where a Vongola Mafia Boss candidate officially gets recognized as the next Boss for the Famiglia. Since the Vongola Famiglia is one of the biggest Mafia Famiglias in the world, powerful Famiglias from all over the world will be traveling to Japan to attend the Ceremony and see the next Vongola Boss for themselves. Also, since the Ceremony is an important event for the Vongola Famiglia to retain their power, it is expected that some Mafia Famiglias will either boycott the ceremony or try to prevent it from taking place altogether.
The Vongola Decimo's Inheritance Ceremony
Vongola Decimo's Inheritance Ceremony was announced by the Vongola Nono after he had learned about Tsuna's fight with Byakuran in the future. If the ceremony takes place, Tsuna would officially be the "Vongola Decimo" and in charge of all the Vongola Famiglias in the world. Reborn says that this would make Tsuna "dominate the underworld society."