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.

Shinichirou Nakagami was living the life other boys from his grade could only dream of—staying under the same roof as prodigal student Hiromi Yuasa. However, the bright and cheerful Hiromi has been depressed and cold at home ever since her mother passed away. While he is the subject of the ignorant jealousy of his peers, rumors begin to spread when Shinichirou meets Noe Isurugi—a girl known for cursing classmates, curses which always end up becoming reality. Noe curses Shinichirou as well, but two pits are created when you curse someone, and her curse on Shinichirou comes back to bite her in the form of a raccoon to her beloved chicken, Raigomaru. Despite this, she does not shed a single tear; Noe had had her tears stolen. For Noe to be able to cry again, she would need the tears of another, and Shinichirou knows a person whose tears he wants to take away.

Ushio Aotsuki is a stubborn middle school student and son of an eccentric temple priest who goes about life without care for his father's claims regarding otherworldly monsters known as youkai. However, as he is tending to the temple while his father is away on work, his chores lead him to a shocking discovery: in the basement he finds a menacing youkai impaled by the fabled Beast Spear. The beast in question is Tora, infamous for his destructive power, who tries to coerce Ushio into releasing him from his five hundred year seal. Ushio puts no trust in his words and refuses to set him free. But when a sudden youkai outbreak puts his friends and home in danger, he is left with no choice but to rely on Tora, his only insurance being the ancient spear if he gets out of hand. Ushio and Tora's meeting is only the beginning of the unlikely duo's journey into the depths of the spiritual realm. With the legendary Beast Spear in his hands, Ushio will find out just how real and threatening the world of the supernatural can be.

Reito Mizuhara is a medical student at the National Advanced Medical School in Tokyo who contracts a rare, lethal disease called cellular sclerosis. In order to be treated, he is put into cryogenic sleep for five years. Upon awakening, he learns that a year into his slumber, a worldwide pandemic broke out, caused by the novel Male Killer (MK) virus which exclusively afflicts males and has killed all other men on Earth. Fortunately, Reito and four other men were spared during their cryosleep and are now immune to the virus. As the only men left in the world, they are thus tasked with mating with as many women as possible to repopulate the planet. However, Reito is committed to his childhood friend and sole love interest, Elisa Tachibana—only to learn that she went missing three years ago. While the other male survivors adapt accordingly to this new world, Reito instead chooses to pursue Elisa, fight never-ending temptation, and investigate this mysterious virus.