Ceres: Celestial Legend
The Day the Moon and the Sixteen Stars Align
S1 E1:
On a day that should be filled with cake and joy, Aya Mikage and her twin brother Aki are instead made to spend their birthday at their grandfather's mansion. Rather than a surprise party, they're met with the grim faces of the Mikage clan. There's only one present--and what's in the box will change Aya and Aki's lives forever.