If you are like me and just finished these after Roku and not by the chronicle order then you would be surprised by the quality of the OVAs and how good they are.
In this OVA you see stuff that wasn't there in ROKU like unique characters and stories, with ROKU being more on the repetitive side and had many mistakes, this however was perfect in the 2 episodes, the characters are really good and their way of thinking is unique that it would make you think that there really are much more important things in life than just surviving or having people around you for
the sake of not being alone.
The first OVA was great with very good characters and the way things were solved was the thing that made me really love it because it was different, it didn't go for the cliche endings that most of the stories have.
The second OVA was the best out of the two because it had that feeling like you are going on an adventure, the story ,the plot structure and the way it progressed was much more enjoyable than the first one with the sense of danger that you feel because the MC could die/get injured at any time which was a very nice addition.
Overall the OVAs were perfect with the soundtracks, art and voice acting being on point, 10/10.
Would 100% recommend it and to be honest, If you made it this far in the anime, then you are probably gonna continue it anyway.