Why did Brian Joo apologizes on twitter???

What did Brian do until he need to apologizes so deeply on twitter?
Check out what had he tweeted just now.....

To any & everyone who was offended by my immature actions from 100 out of 100, I am depply sorry... Won't happen again & I'm not a racist TT

Please forgive me as I admit my faults... Never meant to hurt anyone. I hate no one and only want to share love with the world..sincerely

And if my apology isn't enough, I don't know what else I can do~I am seriously sorry

& I wasn't trying to imitate a certain group of people, but my close friend who was actually on set w/ me that day, visiting from Seattle

But that still isn't an excuse, and I know... But please except my apology for I am hurt that others are hurt... I will pray for you all

p/s:Brian is too upset until typo on the tweets awwwww it should be accept not except
What did he actually said on the show?? Let's see...

He imitated some of the African American actions on the show that brought some negative feedbacks from the netizens.

I think he's just over excited on the show, Brian we do understand you. Don' feel too upset, i am sure they will accept your sincere apologies