You guys this is the Anime NANA!

You see: Starlight Glimmer is voiced by: Kelly Sheridan and shares the same voice actress as Nana Komatsu! & Sunset Shimmer is voiced by: Rebecca Schoichet and shares the same voice actress as Nana Osaki! So,

Sunset Shimmer as Nana Osaki

& Starlight Glimmer as Nana Komatsu! Or the other way around