Note that, don't take this show very seriously, it's a stereotype joke that's being exaggerate. Somehow the problem is just lying with the individual personalities (or so the narrator has been said). Well, it is also common among anime and manga authors to mention their character's blood types, and to give their characters corresponding blood types to match their personalities, you can always refer them to this.
Not much would make this show more entertaining rather than the comedy itself. Blood type A might have something Blood type B don't have, and vice versa. You can see how they're interacting in daily life even though having many differences. You can also see their different reactions from same kind of situations. But note that the personalities they presented aren't very accurate as well. Currently, there's no scientific research that proves the blood type can be much affecting the person's personality. But surprisingly from this show I find the accurately percentage might be 40-60 % since i knew and heard most people have the same weakness or advantage with the characters here. Myself included. Well, yeah my advice you can just take the lessons from here, and take it with a grain of salt.
That aside, the characters design is kind of 'adorable' to the excess that their faces are showing their own blood type, it's so simple.
Might be purposely used for focusing to divides their personalities as well. But yes, it is so simple.
Even the music ED describes their personalities but it did well for trying to tell they should get along with each other too. And for the cast voices this anime really has a great line-up of VA/seiyuus. They're mostly a known people for the popular characters they're voicing, and here I might as well say that the voice is what I could say accurate and most fitting for the characters.
Ultimately, what this anime only lack is the duration, seriously in only 2 minutes the conversation is being rushed like blablabla and blablabla tara! the ED song is playing. It is fine if you can handle fast conversation and understand what's going on but mostly other short series wouldn't do this. You're going to find it hard to get what they're saying unless you press the pause button for every long-and-fast talking they made. I even replay the episode for 2-3 times to really get or understand what's the plot they're hinting.
I recommend this show to everyone, not that it's hard to recognize the comedy in it.. whether it's accurate or not, it's actually just a fun watch!
