It’s not something I see people talk about a whole lot, but I get the impression the fantasy of having a sibling you don’t already have — particularly an older sister — is quite a popular one among certain portions of the population.
I’m not even talking about a sexual fantasy here; I’m simply referring to the idea that some people seem to find the idea of having an older sister quite pleasant. And yes, I’m one of those people.
We’re certainly well-catered to when it comes to Japanese popular media, at least, with a whole host of charming onee-chans out there just waiting to take care of us. The most recent I’ve encountered? Amayo Sato from Gun Gun Pixies.