It could be quietness solidarity... which totally works; they can have each other's backs and nod over things they agree on. Considering Minato also lives with Selen, a shared relationship is always a nice factor, as well.

I'd be happy to have Minato befriend both! c: All the Social Links~ Do you have any ideas as to what tarot arcana they may represent? Usually I gloss over apps and decide for myself, but the CR meme is a good opportunity to ask.