Welcome to the netherworld, Y/n-san!

Prolog II

After that night y/n needed time to mourn her loss and to find the motivation to keep going. Sullivan was by her side to let her know that she wasn't alone. He brought her meals and drinks, let her cry on his shoulder, listened to her recalling memories and rambling about how unfair it was and would leave her alone for a while if she asked him to. He wished he could ease her suffering because it was heartbreaking to watch but he couldn't bring back the dead unfortunately. All he could do was staying with her and helping her in any way she needed.

Some time later y/n had a dream of her parents telling her that they would always be with her even though she couldn't hear or see them anymore and to try to keep smiling since her smile could warm peoples hearts. Afterwards y/n woke up crying and thinking about her dream. She felt a warmness in her heart believing her parents were watching over her to keep her as safe as possible. Y/n wiped her tears and for the first time after the incident she smiled. In that moment she promised that she would make her parents proud by showing that she was a big girl and not worry them anymore. With that promise in mind she waited for the man who saved her, brought her here and took care of her to thank him for this. Now that she clearly thought about it, he reminded her of a grandfather (totally not the white mustache to blame) and told her he was going to adopt her as his grand daughter so she should get used to call him that. It might make him happy aswell!

Just then the mentioned man opened the door followed by a red-haired one with cat ears and tail to check up on her and probably spend the day with her. 'Speak of the devil and he shall appear'. "Good morning. How are you feeling? Do you need anything?"

The girl smiled at them before answering. "Good morning! I'm feeling better now since my parents visited me in my dream. No need to worry about me anymore." Her smile turned bashful but she still continued "Thank chu very much for everything you did for me, grandpa!"

The adult stared at her in surprise before turning into an egg-shaped chibi and jumping around in glee. "Yay!!! Opera, did you hear that?! She called me grandpa! My granddaughter is just the cutest, thanking me even though I haven't done much yet! Which reminds me..." he suddenly got serious again while turning to the other adult who he called Opera. "Can you prepare breakfast for us? Since she feels better, we have a few things to talk about."

Opera nodded and left them alone. Y/n looked at her grandfather nervously wondering what he wanted to discuss with her. He sat down on the chair next to her bed before speaking. "There are a few things you should know about living here. I took you with me to the netherworld, the world of the demons. Humans are mere legends here to most demons and only a few know of the human world like myself. Most will try to eat you if they find out that you are a human but you don't have to worry. I will take precautions to ensure no one finds out and that you will be safe. One of them for example is that I cast a spell on you so you can understand and read demon language. If you still want to be my grandchild then all you have to do is..." he snapped his fingers and a paper appeared together with a stamp. "...to stamp this paper. I won't force you to stay with me but....I would be so glad to have such an adorable little granddaughter to brag about, spend time with and spoil rotten!"

The girl thought about it. If she declined she would probably be brought back to the human world where she would be put in an orphanage hoping a human will adopt her since she didn't have any relatives but if she signed it she would have someone with her who wanted to protect and love her as family but her life would be constantly in danger if she isn't careful....though she was already used to this making this decision an easy one. She grabbed the the stamp and put it on the paper before handing them back to her grandfather smiling.

The demon couldn't hide his joy and gleefully jumped around the room in his chibi form with the contract in hand. Y/n giggled at the sight. After a few minutes he turned back to her in his normal form. "Now that that's out of the way." He snapped his fingers again and this time the whole room turned into a spacious bedroom with more furniture and even toys for her. The girl's eyes widened at the sight. "This will be your room from today on! You can look around it to check if there is something missing. I also bought you some clothes but only a few since I want to take you out shopping once you're settled in. You can come down once you're done since it shouldn't take much longer for breakfast to be done. I have to tell Opera that today is the best day of my life!"

With that said her grandfather left the room happily with a bounce in his steps. Y/n heard him but was still too shocked to do anything. Slowly she fully comprehended what he said and climbed out of her bed. She looked around the room that was now hers and noticed a lot of curious looking items. Making a mental note to ask her grandfather or Opera what these are she went to the closet to pick out clothes to wear (author won't dictate what you wear, besides the school uniform later on. It's because everyone has other tastes, definitely not because author is too lazy to come up with something!).

Afterwards she left her room to join the two demons at breakfast. Her grandfather, who she found out is named Sullivan since Opera called him that, is overjoyed that she asked him if he could tell her what some of the things in her room are since for him it meant spending more time with his lovely granddaughter and they agreed to do that after eating. Even though the girl needed to find the courage to try the food due to its special looks she soon started to ignore the appearance and ate as much as she could. Sullivan encouraged her by telling her to eat up since she was still a maturing girl.

That was the start of y/n's new life.  Thanks to Sullivan's and Opera's help, she got accustomed to her new surroundings quickly and loved spending time with both, even if Opera often took her outside and threw different balls for her to dodge just so she kept her reflexes intact. She simply enjoyed her life in the netherworld with both demons and nearly forgot the warning from her grandfather until one fateful day approximately six months later...