Monster Musume volume 13 features story and art by OKAYADO.

What do world governments do when they learn that fantastical beings are not merely fiction, but flesh and blood--not to mention feather, hoof, and fang? Why, they create new regulations, of course! "The Interspecies Cultural Exchange Accord" ensures that these once-mythical creatures assimilate into human society... or else!

Suu’s been kidnapped! Kimihito and his houseful of monster girls set out to find her, but what starts as a simple search and rescue mission turns dangerous when Suu is forced to face off against a giant slime. A plus-sized water battle ensues and Kimihito is once again caught in the middle–literally! Which slime will reign supreme?