This went from a 7 all the way to a 5 in a matter of chapters. If you ignore the mild homophobia and Ranmaru constantly sexually harassing and sometimes even sexually assaulting Momoko, it's actually kind of a charming story. Then, many chapters later, after they finally get together.... he cheats on Momoko. A lot. But hey, Ranmaru's not actually SLEEPING with the women. He's just flirting, getting their numbers, kissing them, etc. (He literally fingered some lady but it was so he could get important information for Momoko but apparently we’re supposed to ignore it cuz it’s for the greater good? He even knows it was horrible, dodging telling her how he got the info)
There's an entire arc where we learn how Momoko's father cheated on her mother so often that it destroyed her, but in the end, Ranmaru does the same to her, but because he's not flat out sleeping with them, we're supposed to be okay with it.
Note that I deducted the score by a point due to my own rating system, in which I deduct a point if the MC is sexually assaulted by their love interest. He doesn’t rape her or anything, but he feels her up a lot.