Uuu it's great to find out what people have in mind while desgigning their characters hnnnn
Compare to a lot of people, I don't think I spent even that much time designing my characters for :Rebirth... In fact I already had some character concept for the story laying around in my folder collecting dust from a long time ago.

Noah was purposely designed to be young-looking despite his actual age that is close to 30. I wanted to portray a "clumsy" and "inexperienced" father... that doesn't really fulfill well the role of a "father". "Frail" and "Weak" was something I had in mind while designing him because he has health and heart problem ever since he was born. This also explains why I went and gave him a paler skintone compare to the others. He usually looks extremely calm because he is used to keeping himself calm due to his heart problem. If he panics or feeling strong emotion, his heartbeat might get out of control. Noah's choker is probably something that people would remember him by, a very eye-catching choker with a heartbeat monitor that will serve a big purpose in foreshadowing so many thing about Noah later in the story.

Then my other main character: Neo, Noah's son, on the other hand was designed with "independent", "resentful" and "anti-social" in mind. (Or my readers like to call him an emo kid) His look is based off Noah's appearance down to the very eyes color, he is sorta like a mini version of him, but even more quiet. Some people might ask why the airmask? Beside the fact it makes him look even more like an "outcast", he does have a reason for wearing it and it's spoiler so I can't talk about it LMFAO Neo's personality is very mature, sometimes even more mature than Noah, and despite his age, people shouldn't take him for a simple 13 years old either. His action and line of thinking is questionable for a kid, but I assure you all that is on purpose because he is... Neo.
For the gender, because I want to portrait a father-son relationship and the awkwardness between the 2 characters that doesn't really look like they fit the father-son category look and personality wise. Compare to a usually more "motherly" mother, Noah as a father that doesn't understand his son one bit would fit the bill better for me. For the race... I don't really bother myself with race when I draw my character. I'm a minority when it comes to race too but I don't really care what race a character I like is nor would I scream for diversity in a story. People can design whatever kind of character that appeal to them. It can be all Asian, all white, all black for all I care.
Noah is 29 at current time while Neo is 13, I didn't want Noah to be too old nor Neo to be too young so they are what they are LMFAO
Noah ignored Neo for the longest time because- S-S-S-S-SPOILER. 😂