In some ways this is one of the wierdest shows I've ever talked about, it's six half-length episodes (that were shown two at a time so you can just think of it as three episodes) about an ancient Roman architect/engineer who keeps ending up in modern day Japan and is fascinated by their baths. This is a special kind of strange, not where you throw whatever you can at a story and see what sticks but one where you take your incredibly specific passion and attempt to make an entire story out of it. Does it work? Weeeeelll, sort of actually! I believe there's more material in the original manga that the show didn't cover (since the original manga is six volumes like, Yen Press actually publishes it in the US) but I think they made a wise choice in making this series only three/six episodes long and splitting it up into the half-episode format.
This isn't the kind of show where I could go "it's so Japanese" and everyone else would be nodding and agreeing with what I meant, but it is really easy to tell that this was a created by a Japanese person. By which I mean, the entire plot is that every episode is that Lucius ends up in Japan and is oh so amazed at their technology and all of his "innovations" are just things he brought back, heck the show even manages to have a "foreigner has ramen for the first time and has a religious experience because of it" scene! History buffs will probably remind me that the Romans took quite a few of their innovations from all over their empire so this didn't quite bother me as much as it could (and I even learned about a few things, like shower hats!) but I am glad the anime was a short one since having that be the plot for 11 or 13 episodes, especially if they were half episodes so it would be 22-26 stories, would have been rather tedious by the end. But instead each episode manages to be different enough that instead the series was oddly entertaining, although I think the visuals had something to do with that as well.
The show is, in a word, cheap-looking, another reason why it's a really good thing they only did three full episodes. Character's mouths don't seem to be animated quiet right at times, the show is animated as little as it possibly can, and you can easily look at a scene and go "right, they drew this character first, then that one, and then they had five minutes left to draw those two guys and just barely finished in time," I'm actually curious if that was a stylistic choice in the original manga as well with how constant it is inconsistent! I'll admit that the ending song was surprisingly catchy, although I was sad that when I finally found subtitles for it that the lyrics weren't quite as fun as I had hoped, there is no opening song but the short montage they play at the beginning of each episode is possibly the best looking part of the entire show. And finally, the rest of the internet swears that the little bits of Latin spoken in the show were actually accurate but after three years of studying Lating (Classical Latin even, not Church Latin) I couldn't make out a single word Lucius said, although I do appreciate the effort!
I didn't realize it at the time but Thermae Romae has actually been licensed by Discotek (I'm assuming it isn't streaming anywhere legally, or if it is then Discotek needs to have a conversation with google about displaying pirate sites before legal sites) and as mentioned earlier Yen Press is publishing the manga in the US and already has a few volumes out for those who want to check out this series legally and tell me if it looks any better in print than animated! There is also at least one live action movie adaptation of it but I know absolutely nothing about that, it looks like you might be able to buy it on Amazon though.