It has the same concept of a young, teenage girl caught up in her own little world. In Heroine Disqualified, the main girl is stuck on the idea of her life being a manga/drama, while in Switch Girl!!, the main girl is stuck on the idea of being a role model to her peers. Both dramas are very animated and the main girls are both very lively. They also have similar best friends, and the main love interest are both kind of calm and collected. Also, I think that the main girls kind of look like each other.

Both deal with two very different people finding a balance with one another. From Five to Nine has more romance though and is centered around young adults rather than teens.