They were given the choice to leave. But they fell in love with Aporou.
Stockholm syndrome isn't actually a real thing, though since this is a manga that doesn't matter but it's now a disproved theory.
How was is disproved?
I should have said not entirely disproved but it's not actually a properly researched and proved mental illness or condition, as while there is some reports that mention the possibility of it being the victims condition it's not an official recognized psychiatric diagnosis and it has been shown that even those who have been suggested to suffer it have said that it was not the case as the way they acted while kidnapped etc was just the most rational way to react to survive, so they merely faked it to preserve their lives. Basically it's kind of a trope and not an actual recognized condition as there has been no real research into it due to how rare/non-existent the condition actually is. I would have linked articles that explain this but it's not hard to google yourself if you want to know more.
I see..nope I don’t remember that but thanks for letting me kno:0
unless i missed the part of rou offering them to be released home, i will stand by my statement: yup they defs got it cos they still prisoners