In this cutscene when Ryo asks about the Phoenix Mirror in the Russiya shop, we have this part with the Dragon as the Big Dipper asterism on the left and the Cassiopeia stars on the right as the Phoenix.
We have the Big Dipper mentioned a couple more times later on in the games, first with Ren on the roof and later with Shenhua. We also have it as the pattern on the Sword of the Seven Stars.
So far as I know Cassiopeia is never mentioned again. But might it come up later in the story?