http://www.dlsite.com/maniax/work/=/product_id/RJ076999.html

Base +48

I never did understand her fascination with bananas...Maybe it's a pirate thing...(AND NO, THERE'S MORE TO IT THAN THE WHOLE "IT'S SHAPED LIKE A PENIS" THING.)

Base +5

bananas, like most fruit have vitamin c which prevents scurvy, that sailors suffered from if they didn't stock up on fruit for longer voyages. characters often get fascination with some random object to tick the "unique wacky moe personality trait" checkbox, so maybe it was just as simple as "she's a pirate, pirates get scurvy if they don't have access to fruit, so let's give her a banana as a wacky accessory to stand out from the rest."

Base +9