When I read a one shot I always keep it in mind that it is not easy to develop a story and create plausible characters on a few pages. So I think that using the typical approach is understandable. Akuma na Cupid is a story about a girl who likes one boy, and then ends up liking the other boy, who was quite rude and coarse with her. There are shojo mangas which have over 100 chapters and which use the same devices Akuma na Cupid uses and in a less satisfactory way. If you're looking for a shojo pastime you should pick thisone up. The art is really nice, and the story is enjoyable (let's face it, it's rather rare to find a shojo manga which will offer you more than a story of a girl changing her mind, and ending up liking the boy she despised). The characters are less typical then let’s say any Shinjou Mayu character. The girl is a pushover, but not to an unreasonable excess, the bad boy is rude and violent, but not to a point where you'd think he's nothing more than a bully and a rapist.
Akuma na Cupid is short, sweet and likeable.