Tsuki no Shinden

In the great republic of Polaris, five major religions are held in high regard. The protagonist (female, name changeable) serves as a moon priestess at the Moon Temple there, and she's about to turn sixteen. On that day, her mother, Deneb, tells her, "On your sixteenth birthday, you must choose a partner from among the priests of the other temples."
The high priestess of the Moon Temple has always been a female spirit summoner, so she needs a capable partner to support the temple alongside her.
Over the course of one week, the protagonist must pick one of three marriage candidates.
There are nine endings, plus a hidden character.
The love interests' facial expressions have been animated for added flavor.

[Translated from freem]