Tale of the waning moon

the long version

"One of the governing rules of the moon and its inhabitants states, 'A Spirit of the Moon must not directly aid those who seek out the moon.' For breaking this rule and giving aid to his beloved Ryuka, Ixto, Spirit of the Waning Moon, has been imprisoned by the powers that be. Far from being glad of his lover's help, however, Ryuka is livid that Ixto took it upon himself to make such a drastic decision without consulting him first! He stubbornly continues on his quest to the moon and Ixto, but do caustic words await these cursed lovers instead of sweet kisses at the end of their long journey?!"--Publisher's website.