I've been a big fan of Sasaki and Miyano since pretty much the early chapters so when the Hirano and Kagiura manga was launched I was there. I was under the impression this anime was going to be a full movie rather than a few minutes of snippets between the two boys however I do think it is something worth watching. Hirano is a character well known to us through the Sasaki and Miyano anime, since he isn't just Sasaki's close friend but also a loving upperclassman to Miyano. There are a few mentions of Kagiura in the SasaMiya anime, althought we don't actually see himas a character (to my memory he only has one cameo), we hear about him through the other characters. Miyano mentions how Hirano is having his "BL moments" with his roommate while the upperclassmen tease him about him.

The short is in no way enough to properly introduce the characters and add the depth needed for them to stand out, however it does show us a snippet of their dynamic and how they interact while at the same time it brings forth a new dimension to both Hirano, who up until now existed to be Sasaki's close friend and to help him get with Miyano, and Kagiura, who we only knew as a name.

Definitely watch this after you watch the Sasaki to Miyano anime, and if you feel up for it read the manga to see even more of what they get up to, as well as more details on their lives (romantically and not).