The tattoo and piercing thing being secret kind of makes sense to me given how strict Japanese schools are (they might even try to make you dye your hair black if it's not already naturally so) I guess, but it continues to boggle my mind that he probably can't go to public pools and onsens and shit like that at all either because of how ridiculously narrow Japan's view is on tattoos in general. They get so set in their ways on some of the weirdest things over there and everyone excuses it as "part of their culture," but I guess this just seems irrational to me. Some nerd could get a pikachu inked on his shoulder and boom, no more entry to the local public bath for you, tattoos are for yakuza you degenerate.