In Raja, a small country located to the west of Tempest. Rimuru and his companions get involved in a long-running conspiracy that swirls around the mysterious power of the queen. Rimuru and his commander Benimaru also encounter another ogre survivor named Hiiro, a man that used to be the brother of Benimaru.

Self-professed "home security guard" Mahiro Oyama has not left his home in years, secluding himself in his room playing erotic visual novels. This depraved lifestyle causes his prodigious sister, Mihari, to worry about his well-being. In hopes of solving this problem, she devises a plan to rehabilitate him back to normalcy. The first part of Mihari's plan is to concoct a medicine that changes her brother's biological constitution into a bona fide female, much to Mahiro's vehement dismay. Stuck in this predicament, Mahiro has no choice but to live out his life as a cute girl until the effect wears off—if it ever does.

On a rainy afternoon, a male high school student awakens freezing on the streets with no memory of how he got there. His classmate and crush, Karen Inukai, finds him and takes him back to her home where, to his surprise, she starts to undress. She seems intent on bathing with him, though he has no idea why. When she holds him once more, he catches a glimpse of himself in the mirror—discovering that he has turned into a dog! Inukai adopts the puppy and names him Pochita. Now, he must adjust to life as a dog and figure out how to get out of this strange predicament. But while he mulls over an escape plan, Pochita sees a whole new side to Inukai that he never saw at school.

Tricked into assassinating his own prospective father-in-law, righteous samurai Raizou Kurima is overwhelmed with guilt. In order to reclaim his honor, Raizou swears vengeance on the lord who gave him those misleading orders. In his pursuit, he is aided by self-proclaimed merchant-of-all-trades Yuuen Usui, who is actually one of the Revengers—assassins who seek justice for the wronged and dispense bloody revenge on their behalf. Tragedy seems destined to follow Raizou as he becomes increasingly intertwined with members of the Revengers. As he begins working as a vigilante alongside them, the complicated web between the corrupt Japanese political elite, the unscrupulous Europeans, and the Revengers gradually reveals itself. The more entangled he becomes in these affairs, the more Raizou realizes that justice is as deceptive as the honor that he sought to redeem.