Complex sentence: He is a dark, mysterious person who has the appearance of a child, even though he is actually older than he appears, and when she first meets him, Mikan is shocked to discover that he is actually a principal.
Split into simpler sentences: He is a dark, mysterious person who has the appearance of a child, even though he is actually older than he appears. When she first meets him, Mikan is shocked to discover that he is actually a principal.