Yeah, between James and Squid (he was already well bonded to Justin for Diamond-Pearl reasons,) he got close with James fastest, while Dan and Squid were playful rivals for a while. Part of it was a morbid curiosity about humans, since Pink/Lizzie adored them so much as to keep a zoo for them. He wondered what she saw in them, what she saw in Earth that she wanted so badly to stop the colony she begged for centuries for. James was mostly the one who loosened up how judgemental Dan was, having a semi-optimist mentality and finding the good in most things. He always knew the Earth worked in a cycle where every piece mattered, and Dan realized both the beauty of the world through him and how Homeworld was exactly like that. Little things like that. On top of that, James understood grief, the exact same reason why Blue was interested by Greg in the canon show, (maybe not in the specific sense Greg did with Rose, but either way, “I’m surprised that a human being is capable of understanding how I feel…”)