Which chapter of the constellation research museum of Love between Light and Night is unlocked?

The constellation study of Love between Light and Night is divided into two parts: Ursa minor and Ursa major.

You can unlock the Constellation Research Museum on the main line of customs clearance 4-6, and you can also play Ursa minor. It takes 6 chapters to unlock Ursa major, and the specific requirements are in the game (because it has been forgotten for too long).

The main line is completely completed (currently in chapter 8), and the online Ursa minor obtained every week will become 800.