Арк

Arc is a mysterious young man dressed in a cape and fedora. He first meets Yucie when he seeks shelter at a convent at which she is temporarily working. It turns out that he is being sought by the castle guards, which alarms Yucie. Although Yucie is very saucy towards Arc, she finds herself drawn to him. Arc heroically saves Yucie when they encounter a demon from the Demon World. He also calls her "Forehead" to tease her about her big forehead, much to her consternation. After kissing her on her forehead a few times, he finally gives her a real kiss, which is witnessed by her friends. Arc is also hunting for the one that first put together the Eternal Tiara, which he feels will lead him to his real father.

In reality, he is Prince Arrow, son of Queen Ercell. (This is in fact the reason he is being sought by guards, as he escaped from the castle to find his 'biological father'.) At the same time, he is the prince that once saved Yucie when she was in danger when they were small. Later on, it was shown that Arc was also drawn to Yucie. (source : wikipedia)