If you liked the Pet Shop of Horrors manga, the Anime-Planet community thinks you'd like:
High in the sky is the Yume Kira Dream Shoppe, a magical place where any dream can be granted in exchange for something dear to you. Rin, the shop's owner, and his plush rabbit assistant Alpha sign contracts with those in need, from a beautiful tree to a girl unable to confess to her secret love. Using rare and powerful items, Rin and Alpha will help bring joy to many lives.
It's true that Yume is very lighthearted and generally happy, while Pet Shop is very dark and feels like more of a precautionary set of tales. Regardless, you can't deny the similarity between the stories, so if you liked one try out the other (just expect a bit of a different tone)