beta
I get the impression ppl are confused about it. Yurito's lineage is the initial family that dealt with the beasts but it's not the only one. So not all the mates are related by lineage, but coincidentally Yurito and Coro come from related lineages from the original beasts and the first mate, although it's basically negligent how related they are by now. Also, beasts do have multiple mates, so it's possible that there's an even larger relation gap because of it. Point is, it's like 4th or even 7th cousins getting together, there's basically no genetic or even close family relation at that point.