I actually really enjoyed it. The main story, about the Yakuza, is the weakest one out of the three, in my opinion. Although the plot is a bit common (every Yakuza story has that same plot), it was enough to get me crying, which I consider a very good thing, so that's a strong point. The pace was too fast and a little confusing. I had to go back and read some parts again in order to understand the story. Also, I though it should be more evenly spread between the three chapters. However, this weird pace is one of the things that kept the plot interesting.
One of the best things was the art. It was really good, so the expressions on the characters' faces made it more intense.
The uke's a little "dead", doesn't have much of a personality, and the seme is that usual yakuza meanie, but they end up saying some cute stuff to each other.
The second story, "Uknown Letters", was my favorite of the volume. It was not in any version of this manga I could find. But I wanted to read the complete thing and, after reading the reviews, I knew I had to find it. So searching for its own name will probably get you the story. And I would totally recommend it, because it's really good! Although the characters' feelings are quite predictable, I've never seen any plot like this one, and I thought it was really cute. The sex is also very harsh, which in this case makes a lot of sense and makes for a better story. It doesn't have an explicit end, but leaves an open ending that's actually lovely once you see the last page from the manga.
The uke is very strong, which I like, and the seme is the "I pretend I'm cruel but I'm actually so into you" type.
The last story, although one reviewer didn't like it, was also good, in my opinion. If you are the type of person who minds age difference, I wouldn't recommend it. One of the characters is 15, which to me is no kid at all. Also, in the scenario it's presented, it made a lot of sense to me. It's a quick story that's just painful enough to be good, but has a really sweet ending. My only complaint is that I'd wish there was a sex scene. The uke is the common Japanese good boy and the seme's just pervy enough to be so sexy.
A good read if you're looking for something quick, that's gonna grab your attention until the very end!