These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Kikwang using blackface on a reality TV program and acting out African-American stereotypes. The international fandom was not pleased, with several international K-pop news outlets censoring any mention of the incident. Granted, the program was scripted, the cast was told exactly what to do, and South Korea itself didn't have a problem with it all, but several fans believe Kikwang still should have refused to do it if he could.
International fans are divided as to whether Yoseob's reason for defending a Girl Group member from some of the group's more antagonistic fans is either chivalrous or sexist (and whether there is a difference), arguing with each other whenever the issue is brought up.
Kikwang was the one who introduced Yoseob to Cube Entertainment, and Yoseob in turn introduced Hyunseung as well. Doojoon was inspired to become a singer after watching Hyunseung in the Big Bang documentary. Doojoon, Kikwang, and Dongwoon were friends while they were all training with JYP Entertainment. This means that the most of the group was already connected before they started training as an actual group.
The blackface incident, as mentioned on Broken Base, brought backlash from everyone except people in South Korea as the negative implications of blackface aren't understood all that well there.
Yoseob's reasoning for defending a Girl Group member from out-of-line B2UTIES. In patriarchal South Korea, he was celebrated for bravely speaking out against the harassment because it is a widespread problem most Idol Singers are not willing to face for fear of angering their fanbases. To the international fans, however, his reasoning that he defended her because she was a girl rather than just because he felt it was wrong led to arguments as to whether he was being chivalrous or sexist.
Yoseob: "I’m a man, so I can hold it in to a certain point, but that [Rainbow’s Jaekyung] is a woman. I know that she was hurt by the ordeal, which is what led me to write that Twitter post.