Sawerigading falls in love with his twin sister We Tenriabeng, who was separated from him at birth so they would not meet; when he discovers her identity, their union is prohibited as incest. She redirects his desire by describing her exact double, Princess We Cudai of distant Cina, whom he must sail to and win instead.
Reality is structured as an Upper World of gods, a Middle World where humans live, and an Underworld or sea realm, each ruled by divine kin. The human order is founded only when a god descends from above and another ascends from below to meet and populate the empty middle layer.
Human kingship is valid only because its founders are literally gods sent down to fill the empty middle world, making nobility a matter of traceable descent from the Upper and Lower Worlds. Social rank and the right to rule are therefore treated as inherited substance, not earned office or consent.