Azusa caught Delcatty as a Skitty prior during the Light Music Club farewell concert. It is also Azusa's first Pokemon she has caught. It often uses Sing not as an attack but for performances, avoiding the adding effect of putting its friends to sleep.
It was revealed in Skitty's Memorial Backstory!, during a flashback, a selfish Trainer had abandoned it as a Skitty, when Azusa found her unconscious in the rain, so she looked after it. After Azusa nursed it back to health with some medicine and some Oran Berries, she decided to join Azusa.
She appeared as a Skitty in Jumping Over The Moon Stone!, in a flashback and evolved into Delcatty after touching Azusa's Moon Stone. She shares the same personality as Azusa, She is serious, calm, stern, focused on performances, and really loyal to Azusa.
She has good instincts which occurred in the epsiode Sewing With Mio!, she is easily startled and often hides behind Azusa's legs when frightened.
In "What's In a Nickname?", she was finally nicknamed, which she officially named her Cadel by Azusa, and even nicknamed the other Pokemon she has owned.
Her known moves are: Assist, Play Rough, Sing and Attract, and her ability is Cute Charm.