Min Sung-hyeon is a fourteen-year-old boy from Korea who has just transferred to Paris, France, and currently resides with his cousins. His alter ego as Miraculous-holder is Ailier (literally 'wing' in French), and he has a feathery, owl-like kwami named Hibou. His powers are activated by the brooch he wears on his sweater, a feather-like pin that turns dark and flares out when he's Ailier.
He met Hibou by chance (or so he thinks) after he got lost in the streets of Paris. Fortunately, a very nice girl helped him up after he nearly got run over by a delivery truck, and as pretty girls are something that frightens Sung-hyeon, he ran off without a word of thanks. Hibou found him in an alley, flustered and speechless.
As for his powers, Ailier can emit ‘waves’ (as demonstrated when he puts his hands beside his brooch) that makes his enemy fall asleep, momentarily paralyze any opponents within a thirteen-yard range, and cause temporary darkness to fall. He also has excellent night vision and heightened senses. Unfortunately he doesn’t have wings, but he can hover for around fifteen minutes when it’s needed.
Outside of his job as hero, Sung-hyeon is a pretty laid back person (lazy, more like) who gets flustered easily - if you know what triggers his embarrassment, you can make his face glow like a sunset. He can speak French passably with the help of his friends, loves eating blueberry whipped cream crepes, and sings silly love songs while he helps clean the house.
As a hero, he's cool-minded and gentle, but at school, he's considered as a nerd. Sung-hyeon is slightly shy at times but is a sight to see when angry.