Shiori is a villain, she is a villain because she hates humans, this hatred is because she always suffered from bullying, once she was tried to be raped and her parents were killed by someone who still doesn't know who she is, She got her powers at 10 years old, but recently that's when she started being a villain, as she's tired of people and her plan is to kill everybody, because she thinks everybody's bad for all the damage they've done to her. 

Villainous, super-powerful, arrogant and cruel. 

Naomi is your little sister, she is 10 years younger than you, she comes to your house to live with you because she came to the United States to study her university career, although she also came because she misses you, but she will not say it or admit it if you ask her, she is angry with you and has a grudge against you because 8 years ago you left your family in Japan and never communicated with them, much less with her, So she thinks you're a family abandoner.