The yokai world and the demon world, yes.. two very different worlds. But yet, they stay under only one king : Lucifer.
Centuries ago, one of his sons disappeared without telling anybody and for no clear reason. Nothing has been heard from him since. That is why Lucifer has sent his most trusted warrior to find his son, Raum.
...
"TOMOEEEE!" Nanami shouted as she ran towards the shrine
"What is it, Nanami?" Tomoe said as he opened the door, just to find Nanami dashing towards him at full speed, landing face first once she has gotten in the shrine
"Tomoeeee, there was a weird creature chasing me all the way back here," Nanami said to Tomoe while panting
"Aren't you overreacting?" Tomoe replied as he pulled his fan out and put on a you-are-obviously-overreacting face.
"No, I am not!" Nanami said as she stood up, put a hand on her hip, and pulled Tomoe's tail
Tomoe just looked back at her with a flat face, proceeding to whisk his tail out of her hands
"Sorry, I'm just so tired.. ahhh it looked like a little kid that was chasing me," Nanami said as she laid back down on the floor
Without saying a word, Tomoe went out of the room to cook dinner
...
"Young Master, you have received a letter," Sebastian said as he handed a white envelope to Ciel. Ciel took a look at the letter and said, "It's from the Queen,"
He opened the letter and read it.
"What has the Queen told us this time, Young Master?"
"There has been several filed cases of mysterious children appearing in this forest.." Ciel trailed off and sighed.
"What is it, Young Master?"
"In this forest… in japan," Ciel finished as he sighed deeply and rubbed his eye under his eye patch, "But I am the Queen's watchdog, and my mission is to clear away the Queen's worries. Sebastian, we will leave as soon as possible. Get everything ready,"
"Yes, My Lord," Sebastian said as he bowed politely at Ciel and left the room
Once out of the room, he said to himself, "My, my, what else could it be?"