As a note, I don't hate yaoi, I just dislike bad yaoi, like this rather horrible example.
The storyline of this manga is pretty much a bad romance novel. The plot is pretty broken and at times doesn't make much sense. I had to find a synopsis of the manga just to make sure I wasn't getting mixed up. And it basically falls into the category of "It's not rape, you just didn't know you wanted it."
The characters are basically the mail delivery kid and the office worker, and the perverted monkey-game character. Neither chracter (human, not computer) have very little in the way of personality. The delivery boy is seen as caring, but rather ditzy, and the office worker is apparently obsessed with both delivery boy and monkey-game, having no personallity outside of that. Side characters may as well not exist for how little they are seen.
The only saving grace is that it is drawn decently well, which is usually the case with BL manga.