After you finished the main story you have to find the 7 blue flowers scattered around town:
Flower 1: 0:05
Flower 2: 1:17
Flower 3: 1:56 (to get here later flower no. 7, you have to put a flower on Mugi's grave. Sleep at home one night and come back the next day)
Flower 4: 3:53
Flower 5: 4:39
Flower 6: 5:37
Flower 7: 6:09
Return to the rooftop of the empty building with the blue bouquet. Close your eyes, go a little way into the fog and open your eyes again.
https://store.playstation.com/#!/tid=CUSA0...