I think that the sister and her were dating or she was just in love with the sister but when she confessed she got turned down or when they broke up is the same day she got into prostitution based off of the flashback of her in her school uniform crying.
I think that the sister and her were dating or she was just in love with the sister but when she confessed she got turned down or when they broke up is the same day she got into prostitution based off of the flashback of her in her school uniform crying.