Is there a reason why these two artists discographies haven't been merged yet? I haven't found anything that indicates the existence of another Yusuke Nakamura.
For example, in the discography of
this one, he is credited a lot of times along with Megumi Maruo, who in her
official website includes some albums on which she also collaborated along with 中村裕介. And, hey, some of those albums are also listed in the official site of
Yusuke Nakamura.
So, I think this settles the issue.