Hazukashime

I will humiliate those who humiliated me 10 years ago, one by one! !! ――Kana (27), who works as a bartender at a small bar in Shinjuku, dropped out of school after being insidiously bullied by a group of classmates when she was in high school, and her mother died in an accident, and since then she has tended to close her heart. One day, a woman from a past bullying group arrives at the bar, which ignites a smoldering desire for revenge...

source: https://mechacomic.jp/books/142324