I'm going to ignore a guy at work because of his voice
Why would you ignore the guy because of his voice?
I don't like his Japanese accent.
Sometimes it's hard to understand others who have accents, but you shouldn't ignore them because of it. You need to have a relationship with your coworker, so make an effort to understand what he has to say.
Nah, I just wanted to ignore him. I can't understand him anyways, who uses accents anyways.
They have no choice in how their accent sounds. You should try to understand and converse with them, communication is key to success. Show some patience and willingness in conversation and you might learn something from them.