The reason you probably didn't notice Johnny's tattoos is because tattoos are pretty taboo for celebrities in SK, they can have them, but they usually make them cover up on tv so for stage performances and stuff if the tattoo is showing they put flesh colored bandages on top. And then sometimes it's edited out. But Johnny's tattoos can usually be seen on instagram and they even showed it clearly in the Sticker mv. The big one is recent to this year which is also why you probably didn't notice it, bc he hasn't had many opportunities to show it off.
Definitely hoping you do more NCT reality shows! NCT World is really popular and recommended bc its kinda recent and also has all 23 members, but I also highly recommend watching their reality shows in order instead:
NCT Life S1: Bangkok
NCT Life S2: Seoul
NCT Life S3: Paju
NCT Life S4: Korean Food Challenge
NCT Life S5: Entertainment Retreat
NCT Life S6: Chiang Mai
NCT Life S7: Osaka
NCT Life S8: Hot and Young Seoul
Dream Plan | WayV
NCT Life S9: Chuncheon and Hongcheon
NCT Life S10: Dream in Wonderland
WayVision
Mtopia (SuperM)
NCT World 2.0
7illing In The Dream
Boys Mental Training Camp
NCT Life S11: Gapyeong
Stick Together
NCT 127 Analog Trip: Escape From Magic Island (Coming October)