Since you invited me, it's fine, isn't it?" My Regular Customer: A Virile and Devoted Yakuza?!

Chinatsu, a cafe worker, lives with her boyfriend but is constantly bothered by Munakata, a regular customer who pries into her personal life. On her birthday, she comes home from work and finds her boyfriend kissing another woman! Shocked and wanting to drown her sorrows in alcohol, Chinatsu decides to visit a bar recommended be Munakata. There, she gets completely drunk and is about to fall prey to a pickup, but then someone comes towards her...?