Yokubou Shounen
A series of short stories by Naono Bohra, one of which cannot be beat for sheer crack: Chapter Three's hilarious Love Snatcher, in which a man wishes upon the moon for a better world and is whisked off to a desert island to become the bride of the Tiger Spirit. Mpreg isn't plausible at the best of times, so might as well go Full Loon.
Eto Irokoi Zoushi
The Buddhist zodiac inspires this story about Masataka, a shrine priest who tends to all the animals in that zodiac and becomes possessed by each one during their respective month, acquiring their powers, and the cat god, Koma, and his protector, Koutarou, who suddenly show up at his shrine. The first story deals with the exclusion of cats from the Zodiac. The next ones deal with the mystery of Koutarou's appearance, the threat of an encroacher who wants to steal power, and the slow-paced evolution of their romance.
Suzu No Ne Ga Kikoeru