User blog comment:SolZen321/Ultramen Who Should Get a Series/@comment-1733689-20170513135626/@comment-5724614-20170513143034

Justice is a male Ultra and his human form is female, Justice = Balance. It works in a way that he's a no sider, and the fact that his gender change symbolized that he doesn't want to be seen as an either gender.

And one more thing: the magazine said that Justice is the main protagonist of Cosmos vs Justice, since if you watch the movie, Musashi's focus is slightly lower due to him trapped in another dimension, while the movie focuses on how Julie begins to understand humanity more.

@Sol: According to the magazine as well, Justice fighting against Giga Endra is not the first of his treacherous attempt. There are a few times where he went against the Universal Justice's orders.