After watching Star Jewel I was hoping this story would pick up where it left off, but this turned out to be a short and sweet side story. Where this has the same main character (Hatsumi), there are two major differences.
This episode takes place pre-Star Jewel during Hatsumi's school days where she is just discovering her extra 'part'. I personally think that due to this time change Hatsumi's VA is more suiting, as it seemed a tad high pitched before given her womanly demeanor. But it also targets a different type of futanari audience, as it is more playful. After all, a young futa going through puberty certainly is alluring. Especially when the student council president (and Bayonetta-look-a-like) wants a piece of her!
The other big change, which unfortunately has a bigger drawback, that is the animation. Shounen Maid Kuro-kun (same studio) has a side story or prologue which has little animation. The style can be best described as a living manga, but full color. But, the art itself remains high in quality. Though I'm not certain it was Yoshino's work, either way, very similar.
Now that those two are out of the way, overall it was a very cute and sexy short. Certainly had it's moments, it keeps you entertained. My only peeve about it was the sound. This studio seems to be real fond of silly sound effects, as it seems they used a jar of mayonnaise for everything. The climaxing scenes sounded very sloppy at times, highly exaggerated to the point where you have to laugh.
I don't give this low grade because of the animation, let me make that clear. It all boils down to my personal tastes and the fact that is was only a mere 20mins long. A cute bonus, but certainly not reigning over the original. Just average as far as side stories go.