Seventeen-year-old Marco Polo leaves his home in Venice on a trip to the little-known country of "Yuan", in the company of his father Nicolo and his uncle Matteo. Their mission is to deliver the sacred oil from the Tomb of Christ and a letter from the Pope to the Kublai.

As dungeon-like treasure vaults started appearing throughout the land, more and more people began signing up as treasure hunters—risking their lives to obtain the vast riches and ancient relics inside. In the imperial capital of Zebrudia, the top hunter party is the Grieving Souls—a group of six childhood friends led by Krai Andrey, who is thought to be the strongest of them due to having a reputed wide array of skills. However, Krai actually has no special talent. His accomplishments are actually the result of his friends being overpowered. Krai has repeatedly attempted to leave the party out of fear his lack of aptitudes would one day cause his companions' downfall. Nevertheless, everyone around Krai thinks differently, making him feel obligated to remain the group's leader.

Hirono Kenta is your average geeky junior high school student. His childhood obsession has always been Tokusatsu and anime. In fact, he fancies himself as a "Hero of Justice" and often is seen running around in a makeshift costume of his own design called "Wing Man." Most of his fellow classmates thinks he's just a crazy otaku, but his childhood friend Ogawa Miku thinks he's a noble spirit. One day as Hirono is walking to school, a beautiful and voluptuous girlliterally drops out of the sky and into his life. Hirono, bewildered by the event, none-the-less takes the girl to his home to recuperate (this is his duty as a "Hero of Justice"). He also keeps the "Dream Note" so that he can transpose his favorite "Wing Man" costume designs into it. Later, Hirono is confronted by the girl who reveals herself to be Yume Aoi, Princess of the Dreamscape called Botoreem. Her domain has been conquered by the power mad despot, Rimeru and his armies of monstrous "Seed Men." She barely escaped her domain with the power artifact known as the "Dream Note." The "Dream Note" enables its possessor to create anything they desire by merely drawing or writing information within its pages. Rimeru seeks to steal it to become Master of the Universe. She demands that Hirono give her back the book, but Hirono had already begun drawing into the book (mystically linking himself to it). Hirono soon discovers that his designs and notes on Wing Man become reality and he in turn becomes his own creation. Using these powers and abilities, he and Aoi begin their strange and amazing adventure. Along the way, Hirono inadvertently involves all of his friends, especially Miku in his quest to help Aoi free her people and save her father. Rimeru sends his various minions to Earth's dimension to retrieve the book. One his henchmen is the noble yet devious Kitakura who goes as far as infiltrating Hirono's junior high school masquerading as a teacher.

Masahiro is the grandson of the great onmyouji, Abe no Seimei. However, he lost his sixth sense that enables him to see supernatural beings, which is very important for an onmyouji. Thus, he is left with no choice but to try and pick a different career. But one day, a strange mononoke appears, which he names Mokkun, who shows him his true potential powers after fighting a demon. With the assistance of Mokkun, his quest to become the greatest onmyouji begins.