This is where we answer the question: HOW is it that Tsuna, being Japanese, can be head of an Italian mafia branch?
– The very first Vongola leader (Giotto, designated Vongola Primo) established Vongola.
– After retiring and passing leadership over to Vongola Secondo (the second-generation boss), Giotto retired to Japan. Evidently he got married there and had children.
– The usual line of succession in Vongola went on in Italy.
– Giotto’s children in Japan went on and had more generations.
– The Vongola branch kept in touch with this family extension (the 9th boss visited a few times; Sawada Iemitsu, Tsuna’s dad, is part of the operations of the Vongola).
– All other possible successors to the 9th Vongola boss, including his three sons, had been killed (either by Xanxus or by others).
– Xanxus is NOT genetically related to any of the Vongola leaders.
– Tsuna was not killed off because most of the Vongola did not know about Tsuna and this Japanese extension of Giotto’s line.
– Sawada Iemitsu offered his Japanese extension of Giotto’s line as the final resort for the 10th Vongola boss, and this was accepted.
– (Gokudera Hayato is the son of one of the subordinates within Vongola, but is not in the line of succession.)
Picture cred: Vongola.org