In this guide I'll try explain how to get the true ending in CINERIS SOMNIA.
CINERIS SOMNIA has true ending, which you can get if you found four chunks of ash (parts of the Ash Key) in every chapter. Chunks of ash are easily missable (and if you missed one of them and finished chapter you can't get it after), so in this guide I tell you where and when exactly to find them and what to do (if needed).
When Charlotte tell you about Sweet Medicine talk to her few times. She must tell you about her father and his work.
After you gave her Sweet Medicine and receive Letter to Father go to room 216. Go inside (door will be closed if you didn't talk with Charlotte earlier like I said) and get the chunk of ash from the sewing machine:
After events in Dollhouse (where you saw Marie's memory about a secret of the blue bird) go to the pond/river where you earlier pick up the birdcage for Marie. Examine the wooden toy boat and get the chunk of ash:
In the end of chapter when you get all tools needed to open (but not open yet) the coffin in Ophelia's bedroom and saw all past memories (by peeking to all doors) go to Library on the second floor. Get the chunk of ash from hat and umbrella beside lamp post:
On the top of lighthouse examine the desk: