Mahou no Tenshi Creamy Mami: Eien no Once More

The first 45 minutes is a recap of the original series and the remaining 40 minutes has a new story.
Two months after Creamy Mami's final concert, rumors began to spread that Mami was making a come back, and if that wasn't surprising enough, Tachibana starts a "Project M" and that seems to have something to do with Mami's come back. As word of Mami's concert reaches the public, Yuu doesn't believe it. Yuu, Megumi, Toshio, Midori, Kidokoro make a plan to get to the bottom of it.
(Source: Anime News Network)