Teakamamire no Tenshi The Animation

This hentai is a cautionary tale about a failing idol who tries to use sex to revive her career. However, the more she fucks people who she thinks can help her, the worse off (more unpopular) she becomes. She starts off sleeping with people who can obviously help her (her manager, her producer, her photographer), but eventually gets so desperate that she starts having sex with the Help (including the guy who sets up her booth at an Idol convention).

On one hand, her downward spiral is pathetic and hard to watch. On the other hand, the sex scenes are pretty ... hot and it provides insight into the female character -- specifically, their use of sex as a tool to get men to help them. And, just like in real life, sometimes it works and sometimes (as here) it does not.