Born into a new world after a life of stagnancy, Will awakens to the faces of a skeleton, a ghost, and a mummy. Living in the ruins of a city long fallen, the three raise Will as their own. The skeleton— Blood—teaches him to fight; the ghost—Gus—teaches him magic; and the mummy—Mary—teaches him religion and responsibility. Most importantly, they all teach him love. As Will grows up and learns about the world he was born into, he prepares for the day when he must finally set out on his own. For Will, this journey includes a lifelong promise. At their coming-of-age, every adult is required to swear an oath to the god of their choice, with the strength of the pledge affecting the degree of their sworn god's blessing. With his departure approaching, Will must prepare to accept the truth of his undead guardians and embark into a world that even they don't know the state of. Will discovers, however, that every oath must be fulfilled, one way or another.

Bullies often target someone frail and weak—someone exactly like Yuugi Mutou. His beautiful childhood friend, Anzu Mazaki, is always there to stand up for him, but he can't depend on her forever. Katsuya Jonouchi, who is almost always accompanied by his verbal sparring partner Hiroto Honda, doesn't seem like a bad person either, despite always bringing Yuugi trouble. But most of all, Yuugi wishes for a true friend who understands him and would never betray him. Yuugi treasures his Millennium Puzzle, an ancient Egyptian artifact that was brought into his grandfather's game shop. Believing that solving the puzzle will grant him his wish, he completes the puzzle, unleashing a new personality within him—the soul of the King of Games. Dark, twisted, strong, and reliable, the new personality named Yami Yuugi is the exact opposite of Yuugi. Upon any injustice toward him, Yami Yuugi takes over Yuugi's body and forces the opponent into a Shadow Game. The stakes are high as whoever loses shall have a taste of the darkness that resides within their own heart.

Seven Japanese high school students enjoy international renown for their remarkable talents. One day, these friends survive a plane crash only to find themselves in the medieval fantasy world of Freyjagard, where two human races live side by side in a feudal society: the byuma, who have animal features and formidable strength, and the hyuma, who have a small chance of magical aptitude. After being rescued by the byuma Winona and her adopted elven daughter Lyrule, the group pledges to use their advanced skills and knowledge to pay back the people of Elm Village for their hospitality and find a way to return back home. Tsukasa Mikogami, the prime minister of Japan, acts as the leader of these young geniuses and organizes their efforts to intervene in Freyjagard and gather the information and resources necessary for achieving their goals. Believing that there is a connection between their current situation and an ancient legend about seven heroes from another world who defeated an evil dragon, Tsukasa directs the others to learn about the culture around them and search for any clues leading them back to Earth. But he also gives another instruction: to take it nice and easy, lest they ruin this world by giving it their all.

Though he has successfully repelled the latest Wave of Catastrophe, Naofumi Iwatani—the Shield Hero—has no time to rest. Naofumi is spurred back into action when Queen Mirelia Q Melromarc tells him that the three other Cardinal Heroes have disappeared without a trace, and she tasks him with finding them. With no clues regarding their whereabouts, Naofumi tackles a more pressing issue: the worsening slave trade of demi-humans. Determined to right this injustice, he and his friends find their way to Zeltoble, the country of mercenaries, where the illegal sale of demi-humans has become a lucrative business. To gather money to free the slaves, Naofumi and his comrades disguise themselves and take part in underground coliseum brawls, purposely throwing matches to manipulate the odds and eventually secure an enormous payout. However, with the threat of another Wave of Catastrophe looming on the horizon, the Shield Hero must stick to his mission of finding the missing heroes if he wants to protect those he loves.