A fairly fun series, despite its formula having been used over and over already.
Asu no Yoichi builds on the well-known formula where the good-natured, but clumsy and clueless about personal relationships, main protagonist ends up in a house full of girls. Where the main female lead also has a fairly trigger-happy attitude. Does that ring a bell somewhere? Love Hina perhaps?
Granted, there isn't much you can do wrong if you follow the original pattern. So despite the show never going bad, there is also nothing which makes the series to rise above the mediocre level. In that aspect, the show does a lot better than many other shows in this genre and ends up being a fairly enjoyable show.
Animation: Not the main priority.
There is nothing wrong with the animation level, although I'm not the one who could point out where the flaws are. I did, however, notice that there is a fairly low level of detail, but that may simply be my imagination. It felt like it was lacking something, somewhere, but I never managed to put my finger on it.
Character designs are nice; there is a fair bit of pantsu-showing available, although not on a level to make this a grand-scale ecchi series. It does have more fanservice though.
Sound: Nice voice actors.
I didn't think there was much to say about the music, because most of the time the BGM is fairly unnoticeable. The OP and ED were –imho- pretty much okay, but they were nothing outstanding either.
The voice actors were doing a good job though; especially the voice actor who played Wa-san fit very well, but most other voice actors also fit very well. I could point out specific examples, but that would be giving away much of the series and I prefer that the watcher experiences that by him/herself.
Story: It's a comedy, there is not much of a story to start with, but they do involve a lot.
The show starts off with a fairly simply idea, but they do manage to involve much more than necessary. While one could easily imagine the show sticking to the 4 girls and a guy in one house, there are several sidekicks which get introduced in the series. Sometimes this is a good thing as the character actually adds something to the series, but oftentimes the character doesn't do anything worthwhile and ends up being a filler-character after its initial episode-focus.
The result is that there are many sidesteps for the series, which is both refreshing – as the series keeps its pace without getting the same jokes over and over – but also gives you an idea they wanted to do too much with it and thought up ideas on the spot. Seeing how the series is based on a manga from 2006 (and still ongoing with 10 volumes when I write this), it is perfectly possible that those characters will get a bigger role in the series. However, that isn't visible in the anime, giving the series a chaotic feeling where characters sometimes get cast away just because they don't need to feature for the next 3 volumes – which is roughly the span of the entire anime.
The addition of the characters does, however, open new subplots and a broad underlying plot. That by itself is a pretty impressive idea, not to mention that it actually seems to work.
Characters: Pretty standard characters.
There isn't much to say about the characters, unfortunately. While they are all fairly well designed, they do have some depth as there are several times where the creators focus on personal relationships between each other. Other times the creators focus on the personalities and their personal problems. Usually this amount of depth is being used in 26-episode series, but the makers managed to put it all into a 12-episode series. This gives the show a feeling that the show moves forward pretty fast. Unfortunately, it also means that there is so much that many characters get that development and are then cast aside to make place for a new character to get that development.
If they ever make a sequel to the show, the series might be a lot more enjoyable because they can do more with the characters other than introduce a new one and find a relation with one of the already existing characters.
Value & Enjoyment: It's still a fair bit of fun.
Despite the criticism, this series is a fairly fun watch, especially since they make good use of its original formula and broaden it with several side-characters to involve some plot into it. The comedy is a hit-or-miss though and I must admit I have seen better in this genre – just as much as I have seen much, much worse.
Therefore, it isn't as bad as I make it sound in this review, as I still believe it gets a 70-80% enjoyment out of series in this genre. It's just that it is hard to write a good review about a comedy which has nothing outstanding.
Upon the question “Is the show worth buying?” I have to refrain from answering. While I have an opinion about this in most cases, it is usually down to your sense of humor whether you like a comedy or not. While this show doesn't go out of its way to find the most silly, hilarious or ecchi kind of scenes, it is still a nice watch. And that's exactly the point: it has never managed to rise to a high level.
So while it's fun to watch it because you can download it, or watch it on tv, it's not worth the money to actually buy it. But like I said, with comedies it's always a hit-or-miss and perhaps you consider this the funniest show in a very long time.