Souta's original design (Patreon)

Originally, Souta was supposed to keep his hair out of his face. Problem was that however good it looked in my mind, I was never able to draw it in a way I liked. 

Finally, I tried adding some bangs and only then was I satisfied with his look. Here is the first finished concept art of Souta as we know him, with the exception of his school uniform: 

Nao on the other hand did not go through any changes. He's had the same design from day one.

But that'll change in the comic.