It was a series of unfortunate events that led Mina Von Astra to her demise. First, she had decided to go out at night while in a compromised state of mind. Second, she didn't tell anyone where she was going. Third, she left her knife at home. Fourth, she was walking around with headphones on, blasting music that would only worsen her mood.
Whatever the case, she died and left her life behind only to open her eyes once more with the new identity as the Snow Lotus.
This author does an amazing job at world building. It feels very alive and vivid. The characters also feel like real life people and in a way you can connect with them. The characters and the world will elicit many emotions. I suggest to give this shot and read.