The anime series will adapt 20 stories from a number of Itou's manga for the first time, including Tomie, Souichi, and Kubitsuri Kikyuu (The Hanging Balloons).

Tensions are running high among the clans as the Green King begins making moves that threaten to drive the world into pandemonium. Following the death of the Gold King, the safety of the Dresden Slate, the source of power of the Kings, is under threat. Nagare Hisui, the sly and mysterious leader of the Green Clan Jungle, is determined to procure the powerful Slate by any means possible. Standing directly in his way is Sceptre 4, the Blue Clan, headed by their unyielding King, Reisi Munakata. However, the grim sight of his crumbling Sword of Damocles leaves the stability of his clan and all of Japan in jeopardy. Meanwhile, still recovering from their tragic losses, Anna Kushina and her aggressive clan HOMRA find themselves caught up in the Green King’s games. Amidst the chaos, Kurou Yatogami and Neko are left vulnerable while their beloved friend, Yashiro Isana, the Silver King, remains missing. K: Return of Kings tells the struggle of the remaining clans against the Green King’s formidable forces as one final king appears. [Written by MAL Rewrite]

Although everything the young duke touches perishes, his existence is far from lonely. His spirited siblings Viola and Walter, loyal butler Rob, and the eccentric witches Cuff and Zain are regularly livening up his secluded mansion. But it is the duke's flirty maid, Alice Lendrott, who fills him with the promise of a beautiful tomorrow and the determination to break this hellish spell cast upon him. The identity of the witch who cursed the duke has been uncovered thanks to Zain's unique magic and the help of Daleth, the leader of the underworld. However, the villain is a notoriously fearsome and powerful witch, who, enraged by the duke and his companions' trip back in time, torments them even from the afterlife. Moreover, an unexpected loved one reappears, strengthening the duke and Alice's hope to break the curse and finally close the distance between them.

The story centers on Gen Kinokura, a devoted solo camper who treasures his solitude. During one of his usual camping trips, he unexpectedly crosses paths with Shizuku Kusano, a total camping novice. What starts as an accidental encounter evolves into an unusual partnership, as the two embark on what can only be described as "solo camping for two."