HoloNacht

Hololive members are on an island for a vacation. Their manager A-chan, the character you play, goes looking for them and gets shipwrecked. The island is haunted by a ghost which you can either help or fight to win. The ghost has turned inanimate objects and wildlife in the island into monsters. It has created an ever-night requiring a light source (fireflies) to get around. Explore the island to find the lost characters and uncover the ghost.