Coffin of Ashes

Coffin of Ashes in an adventure-horror game made using RPG Maker. As an RPG game, there are no fights at all. You just need to search, solve puzzles, run, or unfortunately die.
The Story
Delilah is an ordinary school girl. She was meant to go hiking with her classmates, but found no one at the appointed time in the appointed place. In order to take shelter from the sudden rain, she enters an old mansion. As her exploration in the mansion continues, she finds many mysterious phenomena that can't be explained. In this mansion covered by ashes, what's the secret hidden deep underground?
In order to meet again, she makes a date with her friends. After going round an infinite loop 101 times, will she successfully escape the mansion with her friends?
Character Introduction
Delilah:
A girl with beautiful black hair. Though she looks weak, she has a strong heart.
Lilin:
A pink-haired girl who loves to wear dresses. Despite the dark and cheerless mansion, she is very lively. What's her real purpose?
Ian:
A grim boy who is scanty of words. He always hides his face under his collar, indicating he has no interest in anything. What on earth could he be thinking about?