Denji is robbed of a normal teenage life, left with nothing but his deadbeat father's overwhelming debt. His only companion is his pet, the chainsaw devil Pochita, with whom he slays devils for money that inevitably ends up in the yakuza's pockets. All Denji can do is dream of a good, simple life: one with delicious food and a beautiful girlfriend by his side. But an act of greedy betrayal by the yakuza leads to Denji's brutal, untimely death, crushing all hope of him ever achieving happiness. Remarkably, an old contract allows Pochita to merge with the deceased Denji and bestow devil powers on him, changing him into a hybrid able to transform his body parts into chainsaws. Because Denji's new abilities pose a significant risk to society, the Public Safety Bureau's elite devil hunter Makima takes him in, letting him live as long as he obeys her command. Guided by the promise of a content life alongside an attractive woman, Denji devotes everything and fights with all his might to make his naive dreams a reality.

In a city filled with anthropomorphic cat-people, Catman lives free of rules and boundaries, doing everything he wants, which often collides with the other iinhabitants of the city. Created entirely in flash, with no spoken dialog, Catman instead speaks in English and Japanese subtitles. The series is spread across three so-called 'seasons', with only the third having been aired.

If not for his ability to take over people's mind and body, Yuu Otosaka would be an ordinary high school student. Though it only lasts for five seconds at a time, Yuu's mysterious power allowed him to cheat his way to the top of his class and enter a prestigious high school, where he continues his dishonest acts. His shenanigans are eventually stopped by Nao Tomori—the headstrong student council president from Hoshinoumi Academy—who sees through his deceit. Through coercion, Nao convinces Yuu to transfer to Hoshinoumi and join the student council. Hoshinoumi Academy is secretly an institution created for adolescents who possess supernatural abilities—with the student council serving as a means of locating those who abuse their powers. With Yuu begrudgingly assisting in council affairs, the group sets out to find and protect new ability users from harm. However, as they further investigate the abilities, their findings entangle them in far more complicated matters than they could ever imagine.

In 3015, the year of Huanli, two countries, Donatia and Kouran, are embroiled in a war of supremacy that is tearing the world around them apart. The small island Nil Kamui has suffered exceptionally from the war, with lands conquered in the name of each kingdom and stolen away from the people. To make matters worse, their deity, the Red Dragon, has gone mad, rampaging about Nil Kamui burning villages and killing people indiscriminately. Ibuki, a descendant of Nil Kamui's royal family, resides at an orphanage and refuses to take on the role of king. Abhorring conflict, Ibuki desires a peaceful resolution, however the chaotic world will not allow for such pacifism when it is being torn asunder by war. Despite his reluctance, Ibuki is drawn deep into this conflict. Can he rise to the occasion and save his country?