Japanese name

From where's the Japanese last name? The credits only give the first. Seelentau 愛 19:20, October 21, 2012 (UTC)

Because they are "Ryūdōin" brothers. Their father had such last name I guess--Elveonora (talk) 19:25, October 21, 2012 (UTC)
I know, but what about the Kanji? They're not given in the credits. Seelentau 愛 19:34, October 21, 2012 (UTC)
Looking through past revisions, ShounenSuki is the one who added it. If I had to guess, he got it from some game related material, the brothers appeared in at least one video game. Omnibender - Talk - Contributions 20:27, October 21, 2012 (UTC)