Ferdinand Rue's Links
Amy is Ferdinand's oldest friend, and the one he reaches out to when he needs help (he doesn't need help often but still) - she is the person he's closest to other than his mother. She is also the only person he has invited to his home planet, thus the only person to have actually met his mother thus far.
Amy loves to tease Ferdinand about his various quirks, as she thinks of him like a sibling given how similar they are in age and life experience. Probably the only half-elf who doesn't lapse into treating him like a child, ever.
Despite considering them an acquaintance, Moon was one of the few people Ferdinand was genuinely afraid of.
Moon thought of Ferdinand somewhat like a younger sibling, feeling the need to mentor him.