I think Zoku Hoshi Mamoru Inu in all its simplicity can be a beautiful sweet masterpiece.
The art is very simple, however, I think this detail helps to make the manga's personality. Its conveys perfectly the feelings and messages from author to readers.
The story is a sequel from Hoshi Mamoru Inu. Both are peaceful mangas, both can take a smile from you, and make you cry, naturally, you just feel the emotions. Zoku Hoshi Mamoru Inu brings a great ending.
It's directly sequel, there are characters from the first part of history, and some new ones. The main ones are mostly people experiencing difficulty in their lives, and we can say the dogs became their saviors, changing their lives. This slice of life is something close to reality, I can say stories like that really happens, what makes Zoku Hoshi Mamoru Inu better and better.
At long last, I'am not sure if everyone will feel the same sensations of me, as a dogs lover, while reading Zoku Hoshi Mamoru Inu. However, even if you are not a fan of puppys, it' s a great experience (maybe not a 10/10).
If you are in doubt, I can say the one hour reading Zoku Hoshi Mamoru Inu will really be worth it. Read this manga, and run to hug your dog, you both are Hoshi Mamoru Inu.