I did not see a review for this so I decided to write one.
First off I recommend watching these specials after watching the main series.
Senran Kagura really ups the ecchi in these specials, and it's sexy as hell!
These specials are definitely for the fans of yuri, shibari (beauty through tight binding so like tied up), boobs, and highly suggestive stuff with ice cream. The ecchi in this is so fricking good and as I said sexy as hell~! The yuri is awesome and shows up in a lot of the episodes, lots of groping going on. I absolutely love yuri and I'm happy
they included lots of it, sadly tho they only grope and don't kiss. The yuri scenes follow the one character messing with another character formula, think of when Katsuragi gropes the other characters in the main series but just more intimate.
The shibari scenes are really nice especially the second one with Ikaruga. There is also some butt fan service which is great especially considering this series is more associated with boobs. My favorite episode is definitely the final episode reminded me of something that would be in Kiss X Sis, Homura even looks similar to Riko~! The final episode has to do with ice cream and tiny shirts it's so sexy, HNNNNNNNNNNNNNG. Super suggestive and totally nsfw~! ♥
Now onto the cons, the main being the lack of lolicon. I saw Mirai in the picture on MAL so I was thinking "aaaaw yeah" but she actually never makes an appearance. I know that many non-lolicons would be fine with this but she was one of my favorites. There is also zero story development in this and it does not continue the story from the main series. This is entirely fan service. They do try to be comedic in this as well but pretty much all of the jokes weren't that great. Despite being DVD/BD only these episodes do not contain nipples, just convenient censoring. Another thing that bugged me was that the credits were completely silent. I know that is a small thing but I just thought it was odd. Still giving sound an 8 tho because of the sounds the girls made.
I rate these specials a 9/10, if you like ecchi then this is a much watch.