The series starts, I believe, with her "boyfriend" breaking up with her since she doesn't have money or at least leads to that eventually early on, I think she ends up getting a loan early on to help pay for his lifestyle--though he claims medical bills for his family. This scene could be part of a different series though.

The main focus is on the ex-coworker who used to be a star in their office so she ends up surprised to find out he works at a restaurant and that frequent patrons/helpers are a bunch of gang members (who are surprisingly friendly). The restaurant belonged to his grandmother/father who he lived with for a period of time due to a troubled life. She helps out on occasion (mostly as a mascot handing out pamphlets) but also works in an office where she has to learn to get a backbone as well.

The boyfriend she liked at the start I think was because he looked like a member of an idol group she liked too--but again the opening segment I may be fusing with another manga series.

Pretty sure its called Dame na Watashi ni Koishite kudasai

I know this because it got in my list. Hopefully it helps

Be kind or get banned