魔法の歌姫クレシェンド・メロディ ～ステージに響く淫声～

Kotori Aoi was a clumsy, cheerful young girl.
She wasn't very good at singing and her coordination was downright lousy, but she dreamed of becoming an idol.
Her dream was answered with arrival of a little pixie named Sharp.
Sharp had strayed from Musicworld and was saved by Kotori. As thanks, Kotori was offered a contract to be Magical Diva Crescendo Melody for one year.
Using her new power Kotori achieved her dream of being an idol in Musicworld.
However, there was a catch. A hidden agenda to that was wet, and horny, and waiting to trap young girls.
The poison of lewd Musicworld had dripped into Kotori when she signed the contract.
Her curtain has risen: welcome to the stage of shame and despair. 

DLsite English