He has a similar personality to that of his younger brother; both seem quiet and serious. Unlike Naoki, however, Masaki has some caring undertones, as he understands Naoki's feelings with society, and tries to encourage Naoki (albeit dully) to find a hobby so that he doesn't end up alone in the future.
He wears an olive green jacket over a black dress shirt. Compared to Naoki, his hair is a less saturated shade of red, and while it is also a similar length, it seems kempt.
- Coincidentally, he and his brother have similar forenames. Both names starts with characters that rhyme (マ [Ma] and ナ [Na]), and both end with the same character (キ [Ki]).