The Demon King Is My Little Puppy

Ye Lingling, a girl from Earth, finds her very own demon king, Yali, by a trash can. But the demon king doesn't speak Earth's language. He can only listen to a sentence from Ye Lingling, then repeat the second half of it.

So, after Yali casts a spell one day...

Ye Lingling: "Y-you, what are you? What kind of spell is that?"

Yali: "What kind of spell?"

Ye Lingling: "Isn't that a spell? Or are you an alien?"

Yali: "An alien?"

Ye Lingling: "An alien, you know? If you're not from Earth, you're an alien!"

Yali: "I'm an alien!"

Ye Lingling: "What planet are you from?"

Yali: "...planet."

Ye Lingling: "The Demon Planet? Are you the Demon King?"

Yali: "I'm the Demon King."

Ye Lingling: "Mr. Demon King, don't eat me, okay? I'm not married yet."

Yali: "I'm not married yet."

Ye Lingling: "Pah, pah, pah! Are you worried no one will marry you? If you could turn into a man, I'd marry you someday!"

Yali: "I'd marry you someday!"

A diviner girl with a loli's body and a mature woman's heart × a good-for-nothing demon king with a demon's body and a puppy's heart

Theme: A world-shaking romance between a demon king and a goddess.