He's a personification of the typical Portuguese man, similar to a Zé Povinho living in the 21st century.
Rouxinol's character is a fado lover, a married man, although he often sings like a bachelor with a very active sexual life.
When he arrived in Portugal he decided to make a CD so he could afford to build a house in Barcarena for him, his wife and the love of his life, the china dogs[1] (to whom he actually made a song called Cães de Loiça, Portuguese for China dogs).
Rouxinol sings in a very relaxed form, often using an unusual way of talking and popular expressions, giving wrong accents to almost every word, and getting rather confused when trying to speak English (once answering "I love you too" to a girl who told him "Fuck you").
Rouxinol's songs talk about the life of an average Portuguese adult male, going from fighting with his neighbour and complaining about the chronic Portuguese wildfires and the government to singing the theme songs of his favourite cartoons as a kid (Abelha Maia and Dartacão).