『距離2』

個人の見解では、

切れ者ほど低姿勢で控えめな方が多い。

There is also a brother in Hokuto.

But,his younger brother isn't akin to Mizuki at all.

In spite of the same"younger brother".

In spite of Mizuki is"younger brother" of Kazuki,He's the adult independent mentally and makes the behavior which can't seem 15 years old boy.

Hokuto is also "brother" with his younger brother.

But,his younger brother doesn't grow up like as Mizuki.