They didn't appear together in KML webtoon. Josh occasionally showed up tho. And their kids had a cameo in the side story.
Chase never appeared. He was always someone who ditch Keith lol. For Josh, he's Emma's brother. He appeared a couple of times. First, during a party when he caught Yeonwoo who wasn't feeling well that time, to which Keith saw and then snapped later on (as usual). The second was, I believe when Yeonwoo escaped. Another would be during Yeonwoo's amnesia. Where they sent Spencer to spend a day with Josh's kids.
thank you :)
To those who have already read the Kiss me Liar, can please someone tell me which chapters there Chase and Josh appeared? ... I want to know and see them there ╥﹏╥