-goes to see if 47 is up yet and is disappointed-
Also, Goldy, I'm going to have a hard time writing something now that you've done that, but I'll give it a shot.
Tegami Bachi is definitely an interesting shonen read, like it's predecessor in this thread. However, unlike Biscuit Hammer taking the traditional shonen setup and playing with it, Tegami Bachi does a lot of stuff just differently than most shonen stuff.
Let's start out by looking at our protagonist, a young boy named Lag Seeing. Already we see some difference from most shonen protagonist as Lag likes to cry a lot. But it isn't just the crying, or even the reason he cries as Goldy points out, that really set him apart. His general demeanor is just that of a polite, selfless child who sets out to try and help other people. He doesn't care about how strong he is and has no real goal besides helping people out. You might cite Kenshin now, but while Kenshin is this experienced assassin seeking penance for his sins, Lag is pretty innocent. This is a guy who is so pure and incorruptible he makes it his singular goal in life to help out other people, even if they don't want help.
So, aside from Lag just being a general nice guy, I love the feeling Amberground carries. Though as dark as it gets later on, even in these first two chapters you can see how crappy it is to live here. Lag's mother is kidnapped! A young girl is treated like an animal! People starve to death because of the rigid caste system! Even the mail carriers have to be the best of the best in order to not have their soul ripped out from them by gigantic bugs. Despite all of this, the manga manages to keep this optimistic outlook(until chapter 44) showing how people will ultimately be either selfish or selfless in this dire land. Even when there are terrible people doing terrible things, the good almost always manages to shine through because of its goodness.
Also, the side character! We're only introduced to a few here, but the entire cast is a great group of people. Aria Link seems pretty no nonsense at first, but it isn't revealed that she suddenly has a heart later in the darkest of moments, it just turns out that you have to get to know her to learn she's pretty nice. Connor, despite being the only important person to look like the extras is really just a fun guy to be around. He'll tease the dude who ordered porn and eat a ton of stuff, and is just a really laid back guy. I mean, if anyone in this series should be insecure it's him, but he's just a nice guy. I guess what I really like about Tegami Bachi's characters is that they're all just a bunch of friendly people without being carbon cutouts of each other.
Though we don't get to see much of them besides Roda and Niche in the first volume, the dingos are pretty fun. Fish has mentioned Hazel Valentine, who despite being partnered with the grumpiest guy who might be good, he's a fun guy who is a Friend To All Living Things. Gus, Connor's dingo, doesn't really seem listen to him, but when they actually get into battle you get to see the trust between the two and how well their dynamic works.
Also, for those only reading the first volume, there is more plot to it later, with terrorists and stuff. It works really well.
So yeah, like Goldy, I think it's pretty cool.