Alto is a secondary character from Lady Jewelpet.
Alto is Momona's older cousin and Lady Diana's husband.
He first appears in episode 1 as he marries Diana. Momona has a crush on him and therefore doesn't like the fact that he's getting married, however this changes when she meets Diana.
Before the beginning of the series, Alto proposed to Diana during their date, despite their difference in skill at being Prince and Petit Lady respectively, and both made an eternal oath in the Music Box Museum in the Jewel Mountain, also obtaining a Music Box which Luea has hidden.
Alto didn't have the qualities needed for being King and dropped out, forcing Diana to drop out from running for Lady Jewel and run away with him. This however caused Luea to think that Diana abandoned her to be with him.