Responses
yep yuji and kou are half-brothers. but hayato is their sister´s son (from their father´s remarriage). kou´s mom is hayato´s grandma. yuji and kou are hayato´s uncles. I think my explanation is a mess XD here I foud this, I hope it´ll help
http://www.mangago.me/read-manga/stay_gold_hideyoshico/mh/manga/stay_gold_hideyoshico/v02/c007/pg-2/
Just a second,i don’t get this. Kou and Yuji have the same father(Nakayama) right? And Kou’s mother is the same mother of Hayato’s mother.