Storyline

A story about falling in love with the world again. Somewhere else, a world inhabited by people with "stars, A world in the night sky where the sun never rises. A "city of lights" where people live by the light of the stars. The protagonist has lost his precious star. When you lose a star, you lose your memory. There must have been something he should have done. In order to remember what he should have done, The protagonist searches for pieces of stars in the "City of Light" with the ghost Shiromaru in order to remember what he should have done. What are the memories he recalls and what is the "thing to do"? ......