From the TWEWY Wikia:
"Megumi" is a unisex name, just like "Makoto", though the name "Megumi" is more typically used as a female’s name than as a male’s. Megumi is sometimes referred to as "Shades", thanks to his distinctive sunglasses, or "Megs", a shortened nickname for "Megumi". In the manga, when Minamimoto refers to Megumi as "Megs", Konishi snaps at him, saying that Megumi should not be addressed as "Megs" because it could bring back to him childhood memories of being teased for having a girl’s name. Megumi verifies it by stating that Konishi’s statement was "salt on wounds", and was correct.
If what she did say was true though, his traumatizing childhood memories of being picked on could offer some insight as to why he sees the people of Shibuya as its problem, and the fact that he was teased because of his being different from others in that he had a girl’s name might explain why a world of absolute conformity appeals to him so. This means that all of his plans involving the O-pin might have a direct connection to his name. Note, however, that the manga is not canon to the game, as he doesn’t seem to mind or notice when Sho refers to him as ‘Megs’ during the first week. Of course, he could have simply gotten used to it.
The kanji for Kita-niji Megumi literally translate to: North, rainbow, blessing. His first name uses a rarely-seen character with the “dragon” radical in it, which may refer to his second Noise form.
And here’s your silly TWEWY edit for the day:
Though in all seriousness, the wikia makes an interesting point about Kitaniji’s name. We’re probably just thinking too much into it, and I don’t consider the manga canon, but it is possible - and it makes much more sense - that Kitaniji would like the idea of everyone conforming to one single thought because of childhood experiences with his name. Of course, there are probably other factors, but you’d be surprised at how the little things, such as name calling, can affect the person you will become in the future.