kksk
Japanese abbreviation for "koko suki" (ここすき) which means "I like this bit" or "I like this part". Mainly used on video-sharing platforms like bilibili or niconico when commenting on a certain part of a video. It's also used on Youtube but you have to indicate the timestamp, as the comment system is different there.
*Something hilarious happens in a video at 5:08*
"5:08 kksk"
"5:08 kksk"
kksks
shehshah
kksks