I have a dream that one day Negom will draw Rikka going down on Makoto for once. Seriously, is like Rikka is such a pillow princess and Makoto is addicted to the other's pussy or something.
... Well, this is a novel ship (pun unintended). There's nothing that really connects any of them to each other beyond being shipgirls of the Imperial Japanese Navy that served during WW2, is there?