On Christmas Eve, Hiro Hirono runs into Miyako Miyamura, a frivolous girl who borrows his bicycle in order to chase down a purse thief. After Hiro finds his bicycle wrecked and Miyako unconscious, the two unexpectedly spend their Christmas Eve together, and when they discover they go to the same high school, their accidental relationship develops even further. This sparks the jealousy of Hiro's childhood friend Kei Shindou, whose pure approach to life catches the eye of Kyosuke Tsutsumi, a womanizing photographer searching for the perfect shot. Elsewhere, Renji Asou, a boy who dreams of being a girl's knight in shining armor, has a chance encounter with Kei's twin sister—the overly shy Chihiro Shindou, who spends her time reading alone—at an abandoned train station. The two quickly become friends and eventually decide to write a novel together. However, when Renji discovers Chihiro's secret, his childish ideals are put to the test. Guided by two mysterious adults, these youths' relationships intertwine in a heart-rending tale of love, rejection, acceptance, and memories.

Continuing his adventure to get stronger in order to traverse deeper into the Dungeon, Bell Cranel wanders the Orario city streets with his friends and the goddess Hestia. That evening, the city is filled with stalls and games as it celebrates the Holy Moon Festival. Hermes, a god, hosts one such activity where participants are asked to pull a spear embedded in a crystal boulder; those who succeed will receive a special gift: a trip around the world and a divine blessing from the gods! Bell and his merry group challenge one another to claim the prize. But behind the facade of an innocent party game lies a preface for a daring quest ahead.

The Armed Detective Agency is still on the run from the Hunting Dogs, but not all hope is lost. Detective Ranpo Edogawa has a plan to prove the Agency's innocence and save the world from chaos: to find and capture Kamui—the leader of the terrorist organization Decay of the Angel. In order to determine Kamui's whereabouts, Ranpo and his colleague Atsushi Nakajima must convince Ouchi Fukuchi, the renowned captain of the Hunting Dogs, for amnesty. Although Fukuchi was tasked with arresting the members of the Agency, his past with the Agency's president, Yukichi Fukuzawa, may be the key to earning his trust. But unbeknownst to them, Fukuchi might not be as honorable as he proclaims.

Eighteen-year-old Dale Reki is a skilled, kind, and respected traveler, acknowledged as one of the leading adventurers in the city of Kreuz. One day while on the hunt for magical beasts, he comes across a sweet devil girl named Latina. She is alone, dressed in rags, and bears the devils' symbol of a criminal: a broken horn. Concerned for her wellbeing, Dale decides to ensure Latina's safety by bringing her to his home, eventually leading to him adopting her. Latina is sweet, innocent and compassionate, charming Dale beyond his expectations. He begins to enjoy the life of parenthood— experiencing the trials that come with raising a child and coping with the heartache he feels whenever his busy lifestyle as an adventurer parts him from her. Although work and life as a new parent become reassuring constants for Dale, the mysteries surrounding the girl remain. Why was Latina alone in the forest, and why does she harbor the symbol of a criminal? At the same time, Latina also begins to learn about the world and herself as she adjusts to her new life with Dale.