Highschool DXD : BLOOD BROTHERS REUNITED [VERY SLOW UPDATES]

Y/N Hyoudou is a high ranking member of a yakuza. He has been estranged from his younger brother, Issei, for his entire life. When Y/N decides to pay Issei a visit, he is shocked to learn that Issei is a devil and the host of Ddraig, one of the Heavenly Dragons.

Y/N is initially skeptical of Issei's claims, but he is eventually convinced that Issei is telling the truth. Y/N is also impressed by Issei's strength and determination. The two brothers eventually reconcile, and Y/N agrees to help Issei in his battles against the other supernatural factions.