It’s a bit confusing at the beginning of the story but fits in well after watching the previous 12 episodes. From the preview of this OVA based on the previous episode, viewers can get a pretty good idea of what the story will be like. The quality remains the same, and there’s nothing particularly special compared to the previous episodes. However, there are at least a few differences from the previous episodes. This OVA presents a different ending than the usual cliffhanger, making it the ideal episode to truly end the series. The possible reason it wasn’t aired on TV is probably because there's anunexpected surprise compared to previous episodes, so it’s somewhat understandable and might slightly satisfy viewers’ expectations when they’re interested in watching this series—though it’s a shame that some people might not be knowing about this.