subaru and seichiro appears again in the manga x/1992 also called X
they are on opposite sides and they also have their final battle there if you're interested
its X/1999
and Seishirou
http://www.mangago.me/read-manga/x/
warning, it's not finished ヽ(`Д´)ノ
What chapter?
Oh... This manga was so great that I don't know how I should describe these feelings, which I have right now... This story had everything. Happiness, joy, loyalty, love, treason, hope, pain... In other words, it has everything like real life has. Wonderful story.... Amazing manga... I'm happy that I had read this wonderful masterpiece...
On the other hand, I can't believe that I'm first who has written this praise here. Though, this story is so wonderful....It deserves at least one or two compliments... Sometimes people just can't see what they have right in front of them...