Samuel da Costa Mendes is a really bad pun.
As a nurse, his first name is a pun with the emergency medical services both on Brazil and France, plus he follows the biblical naming scheme of the rest of the cast -- Gabriela being his sister.
"da Costa" means "of the shore" in Portuguese, a mention to him inhabiting one of the fake islands created by mankind as a safe heaven. It also contrasts his narrative foil, whose surname is Almeida -- a Portuguese corruption of Arabic for "from the plateau/mesa". Thus, we have a character who descends from the sea, and one who descends from a great plateau.
Mendes, similarly to SAMU, is a joke with his status as a nurse/healer -- it sounds similar to "to mend".
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