Rei Ichidou, Gou Reietsu, Kiyoshi Shusse, Jin Daima, and Dai Monohoshi are five mischievous boys attending Ichiou Junior High. Each with an eccentric personality and a knack for chaos, they've earned a reputation as the infamous "Kimen-gumi." One day, new transfer student Yui Kawa and her friend Chie Uru encounter the group and soon find themselves drawn into their antics. Around them are other colorful cliques—from the handsome "Iro Otoko-gumi" led by Shou Kireide, to the delinquent "Ban-gumi" led by You Nihiruda, the athletic "Ude-gumi" led by Kai Undou, and the tough girl squad "Onna-gumi" led by Jako Amano. As time passes and a new spring begins, the everyday lives of these eccentric students unfold in a lively and comedic school story.

Nori Kamitsuki has recently moved to the Gunma prefecture from Chiba, following after Otoya Todoroki, a former friend who moved there in elementary school. While on the way there, he receives an ominous text message from Todoroki telling him to turn back and that once someone enters Gunma, they never return. Ignoring the message, As Kamitsuki goes about his school life and makes new friends. These people make it their mission to prove any negative stereotypes surrounding Gunma wrong and show Kamitsuki all the ways Gunma is different from the rest of Japan—from its local foods and landmarks, the changes to its daily school life, and even the attitude of the people who live there. Gunma is widely regarded as the least popular prefecture in Japan, but they clearly don't know Gunma yet!

The mysterious, yellow-masked Storyteller is a man whose true name and origin are both unknown. He appears at dusk where children gather and recites sinister tales based on Japanese urban legends, to which his young audience eerily intakes. However, the Storyteller is no ordinary teller of tales. He incorporates a kamishibai, a traditional paper-scrolling device, to add visuals to his already demented narration. A series of short horror stories, Yami Shibai begins with a bachelor who, after moving into a new apartment, immediately starts sensing a malevolent glare being pressed into him. A single talisman rests on his ceiling, but he has no way of knowing it is one of the few safeguards that separate him from a bottomless pit of suffering. Each story is more terrifying, more appalling, and more sickening than the last as the Storyteller's audience find themselves being sucked into the vicious world of his words.

Akina and his friends, having strayed into the Fantasma, find their path blocked by "Fantôme Fighters". The only ones who can stand against them are the special "Mythisch Fighters" chosen by the cards. What is a Fantôme Fighter— The collective name for those who confront reality and fight to protect the fabricated. What is a Mythisch Fighter— The collective name for those who withstand the Fantôme and fight to protect the real. Will the parallactic be erased, or will it become the verity? —Stand up and fight with your existence on the line.