I need help finding this straight Romance manga

Hi! Like most people on here I lost a bunch of manga from my library. I’ve searched everywhere for this one but no luck.

It's a straight, romance, and spicy manga. The mc is a woman in her mid 20s.
She sees her old boyfriend who now works at her job.
They only separated because he was older and was going to college while she was in highschool still.
They get back together and it's wonderful. Plus she always wears matching set bra and panties lol. They get engaged and she finds out he has to go to Germany for work for 2 weeks so they go long distance but everything works out beautifully and yeah that's pretty much all I remember
Please help me! Thank you