A lot of my characters are inspired by real people. Often times, I'll design my characters before I develop character traits. My characters traits will change over time according to what I watch, who I see, and what I listen to.
Jong-ho (one of the protagonists) was based off of Chris McCandless (go read Into The Wild it's a good book). He's smart and a deep thinker, but arrogant and thinks he knows everything. He helps a lot of people, but also hurts others without knowing.
Jung, Jong-ho's older brother was based off of myself. We both have a stutter, we're socially awkward, we're deep thinkers, and we procrastinate a lot. We also don't belong in society.
Just recently, I discovered Elliott Smith's music and I was like "holy cow! This guy is so much like Jung", so there's a bit (actually a lot) of Smith in Jung. The way Jung talks, and forms relationships with people as well as sings mirrors Smith (Jung's a musician). Jung is also inspired by Beck (another one of my favorite musicians) so a lot of what he says doesn't make sense, he also tends to dress in 90's clothes, and has an indie rock style.
Bora was based off of Kumatetsu, the bear man from The Boy and The Beast a drunk, a martial artist, selfish, moody, and funny person who gets frustrated when things don't go her way. She's also a version of myself that I wish I was. Strong, and brave. Like me, she can bounce back easily.