ohh there was a side story or short comic strip where his classmates and his grandpa helped iruma paint his nails... i think this happened during the music festival arc
It started when he is learning to play piano for the music festival. Iruma's nails got a bit ruined because of it thus Azu recommended the nail polish that will help restore his nails. Iruma prolly likes the look of it in his fingernails that he didn't mind staying that way. Hopes that help.
It also suits him and made him more like demon like as all of the demons do have black nails
Oh! Thanks for the replies! Yeah, that helpedヾ(❀╹◡╹)ﾉ~ i have quite the ongoing list of things to read along with fanfics, i tend to forget about certain stuff when quite a while has gone by before they updated again.
And yeah, it does suit himヾ(☆▽☆)
Since when did Iruma's nails become constantly black?? Or rather, why?? Kinda slipped my mind