A decade ago, princess Krystal Novaty “Hime” Nokanatika traveled from another world to escape assassination attempts by an evil force. When she arrives in modern-day Japan, she encounters Haruto Satou. With him she shares a promise: he must forget what he has just witnessed, and the two will become friends. Now heading back to the Nokanatika Kingdom to fulfill her royal duties, Hime bids farewell to Haruto. However, when the young man suddenly remembers his first meeting with Hime, he rushes to the location where she first appeared and crosses the dimensional portal to be reunited with her. His arrival disrupts the marriage ceremony between Krystal and prince Marmarugias Gisaras. The wedding is brutally interrupted by the attack of an abyss monster who threatens the princess' life. Acting impulsively, Hime decides to exchange rings with Haruto, which grants her new husband light powers that permit him to slay the monster. Now dubbed as the Ring King, Haruto must marry four other princesses to acquire new magical powers and have a chance to prevail in his fight against the enemy of the world: the Abyss King.

students of Daikoku Welfare Academy—a boarding school where they are educated, protected, and monitored—the mythical Santa Claus is a forgotten character of fiction. For the adults, Santa Claus is a very real menace that needs to be neutralized by the Saint Nick Pursuit Unit in case he makes an appearance. Shiori Fuyumura, a student of Daikoku Welfare Academy, is determined to find her best friend, Ichie Ono, who has been declared dead after being missing for six months. One morning, Fuyumura summons her fellow class representative, Kazushige Sanda, only to attack the unknowing boy. She is convinced that Sanda is the descendant of the infamous Santa Claus—the only person who can make her wish of finding Ono come true—and is determined to force out his dormant true self by any means necessary.

Abandoned as a child by her mother, Aoi Tsubaki has always had the ability to see "ayakashi"—spirits from the Hidden Realm. Shirou Tsubaki, her grandfather who shared the same ability, took her under his wing and taught her how to live with the ayakashi in peace. When her grandfather abruptly passes away, the independent Aoi must continue her college career, armed with only her knowledge in cooking as a means of protection against the human-eating spirits. In hopes that the ayakashi will not turn to her or other unknowing humans as a tasty meal, she takes it upon herself to feed the hungry creatures that cross her path. After giving a mysterious ayakashi her lunch, Aoi is transported to the Hidden Realm, where the ayakashi reveals himself to be an ogre-god known as Oodanna, the "Master Innkeeper." There, she learns that she was used as collateral for her grandfather's debt of one hundred million yen, and that she must pay the price for her grandfather's careless decision by marrying Oodanna. Aoi valiantly refuses and decides to settle things on her own terms: she will pay off the debt herself by opening an eatery at Oodanna's inn. Kakuriyo no Yadomeshi follows the journey of Aoi as she proceeds to change and touch the lives of the ayakashi through the one weapon she has against them—her delicious cooking.

Azusa Kannawa, ace of the publicity department, is known for her unmatched reliability. Her coworkers, on the other hand, find her no-nonsense demeanor intimidating. Yet, unbeknownst to them, a socially awkward woman hides underneath the facade, simply struggling with casual communication and masking it with a strong attitude. However, her mask begins to crack when a promising rookie, Yuu Kamegawa, joins the team and Azusa gets assigned as his mentor. Determined to guide Kamegawa just like how her senior once trained her, Kannawa puts utmost effort into showing him the ropes. But as they grow closer, she slowly lowers her guard, gradually revealing that the seemingly rigid department ace might actually be far kinder than anyone initially thought.