The 19th volume of Hiroyuki Asada's Tegami Bachi (Also called Letter Bee) just came out in Japan this past Saturday, and lists that the 20th volume (due out this winter) will be it's last. The manga began in Monthly Jump in 2006, and when the magazine ended it switched to Weekly Jump before finally finding a new home in Jump Square in 2007. The manga tells the story of a young boy named Lag Seeing who delivers mail as a “Letter Bee”, coming across all sorts of dangers which his “Dingo” companion Niche protects him from. The 17th volume was just released by Viz in the US last November.
This is a series I remember liking well enough when I got to read a bit of it in the US version of Shonen Jump, so I really need to get around to checking it out more properly eventually. I remember that Niche is adorable and sassy, and that's more than enough for a read, I'd say.