>>41804441
Kaguya would be the easiest member of Eientei to get along with, really.
Eirin is a sociopath, Reisen a cowardly little bunny, and Tewi just likes to fuck with people.
Meanwhile, while she's definitely very sheltered, Kaguya enjoys the Earth and its inhabitants, and spending time with them. If you were to just have fun with her and be her friend, instead of trying to immediately marry her, she'd probably take a liking to you. Until Eirin kills you, at least.