わがまま
わがまま · wagamama · JLPT N3 · na-adj
selfishness
我が儘 = waga (my own) + mama (as I please): my way only
Waga is an old form meaning my or one's own, and mama (儘) means just as it is, or as one likes. Put together, it describes someone who insists on their own way. The noodle chain Wagamama took its name from this word.