Update (2020/04/20): I don’t know exactly when, but Amane Ruri’s doujinshi works were licensed by Irodori Comics, therefore they are no longer available on exhentai/e-hentai and I’ve removed download and read online links to this story. Please do not ask us about where you can find our scanlation for it; try to support the official translation if you can. Thanks!
Setsuko and Masa have an argument over their plans for entering the workforce, which leads to Setsuko storming into a hamburger joint while wearing a Playboy bunny-style costume. But as is often the case, the couple is able to work out their problems, then engage in fun costume sex.
Chapter 9 of Aoki Kanji’s tankoubon “Sayonara, Oppai” (さよなら、おっぱい). The whole tankoubon is now complete; look forward to a special post soon-ish.