How nostalgic
According to the artist, this is supposed to say ๆใใใ(natsukashii) which means fondly remembered/nostalgic but it looks like they got the last letter wrong so it says "natsukashiu", at least based on the Windwaker Hylian I've found. This could also just be sloppy writing and be ๆใใใ(natsukashiku) but you'd have to assume they forgot a part of the character to make that work