Sevusevu is a traditional Fijian protocol and involves the presentation of kava (bundle of waka roots) to the village chief upon arrival or to someones home you are visiting generally for the first time. It's a gesture of respect and sets up a more meaningful relationship between the host and the hosted. When a visitor has their sevusevu accepted, they become part of the larger village family. By receiving something back – usually sharing in grog (the kava root mixed with water) – the visitor acknowledges this obligation.
The sevusevu is also used in a wider-sense with other Fijian protocols such as for reconciliation purposes, with a tabua when requesting land or a daughters hand in marriage and so on.