Eromanga-sensei OVA has two episodes, one focusing solely on Elf Yamada, the other, of Masamune getting sick and Sagiri having to tend to him while getting some of the cast into some hijinks with Sagiri going into *ahem* unknown territory...outside her room!
Elf Yamada's episode was great to be all honest as her light novel has gotten an anime thus celebrations are in order, that is until Elf's mother voiced by Sayaka Ohara comes along forcing her to pack up and leave to find a better suitor, but Elf doesn't want that and this episode not only shows Elf's family circumstances and the like but also shows Elf in her prime in the most out of nowhere musical number LA has seen and it was GREAT. *ahem* Elf Yamada best girl fight me. All in all, as much as the familial conflict is cliche, how it was executed was surprisingly refreshing and again out of nowhere in a good way.
Masamune's sick episode though the episode confines itself in Sagiri's house, the hijinks does arise from the characters outside of the house as most of the cast comes in to actually interaction semi-face to face with Sagiri, as Masamune had always been the proxy for Sagiri in a ways, so seeing the middle man cut out and seeing the interactions were entertaining to say the least, with Muramasa being a highlight. But what Masamune being sick gives us a Sagiri focused episode really and seeing now Sagiri in the role Masamune had always been in and seeing her both tend to Masamune and deal with his day to day chores (and even an allusion back to the ending theme) and friends in the process was interesting funny to say the least and lastly once again reaffirming Sagiri's sibling love to Masamune.
Not much to say in the production front as it's the same as it was in the original season, with A1-Pictures at the helm and doing some decent amount of detail to the simplest things and the always vibrant character designs and yes this is an OVA, thus showing some skin is in order, well yeah there is, but like the original season, they never go too far so fanservice is rather bare and rare either way. Voice acting wise, LA will easily give Minami Takahashi MVP of this OVA purely for Elf Yamada, though Saori Oonishi as Muramasa and Yoshitsugu Mastuoka as Masamune does have their standout moments and heck LA will throw a bone and say that Akane Fujita as Sagiri has her moments as well.
Eromanga-sensei OVA is decent if your wanting more Eromanga-sensei and some different settings for the characters to be in or a celebration of certain characters and this OVA does just that.
