Following in his father's footsteps, Luca must find the hero who wields the zenithian sword to save his mother from Ladja. Based on Dragon Quest V: Hand of the Heavenly Bride game's story. (Source: Apple TV)

When regular salaryman Yoshida wakes up one Sunday morning after a long night at the bar, the last thing he expects to see is that his tiny apartment has a new resident—an unfamiliar high school girl. The previous night, despite finally gathering the courage to confess to his boss and longtime crush, Airi Gotou, Yoshida was rejected. After drowning his sorrows at a bar with his good friend Hashimoto, Yoshida headed back to his home in a drunken stupor, only to run into Sayu Ogiwara, a runaway high schooler. She asked him to let her stay the night, and with his judgment clouded by alcohol, Yoshida complied. Now, with his head on straight but with no memory of last night's events, Yoshida has Sayu explain just how she ended up sleeping at his apartment. Having listened to her story, Yoshida finds himself unable to kick her out—especially after learning that she came all the way from Hokkaido! So, despite his reservations about sheltering an underage girl, Yoshida allows her to stay, and their life together begins.

Former ace runner of Sendai Josei High School, Kakeru Kurahara is chased away from a convenience store for shoplifting. Shaking off his pursuer, he runs into Haiji Kiyose, another student from his university. Haiji is impressed by Kakeru's agility and persuades him to live in Chikusei-sou, the run-down apartment where Haiji resides along with eight other students. Having lost his entire apartment deposit at a mahjong parlor, Kakeru accepts the offer reluctantly. However, Haiji reveals a secret during Kakeru's welcoming party: the apartment is actually the dormitory of the Kansei University Track Club. He unveils his ultimate goal of participating in the Hakone Ekiden—one of the most prominent university marathon relay races in Japan. Unfortunately, all the residents apart from Haiji and Kakeru are complete running novices. Worse still, none of the inhabitants are even remotely interested in being involved with Haiji's ridiculous plan! With only months before the deadline, will the fourth-year student be able to convince them otherwise and realize his elusive dream of running in the Hakone Ekiden?

Fudou Aikawa and Desumi Magahara have just started dating, but no one is allowed to know! Nicknamed Red Gelato, Fudou is the leader of Gelato 5, a group of heroes dedicated to protecting Japan. On the other hand, the Reaper Princess Desumi is one of the combatant leaders of Gekko, an evil secret society bent on world domination and considered Gelato 5's greatest foe. As they pretend to be mortal enemies, Fudou and Desumi sneak away from battle to spend time together. Despite their inexperience with romance, Fudou and Desumi strive to make their relationship work while avoiding suspicion from their comrades. With their loyalties divided between each other and their respective sides, the couple will have to stay on guard if they want to keep their love a secret from the rest of the world.