Jougorou Kobato has a habit of inserting himself into other people's problems. After realizing his detective skills are neither wanted nor appreciated, he makes an agreement with his shy friend Yuki Osanai to become ordinary together. Now entering high school, they aim to be perceived as regular people, yet Kobato cannot help but fall back into his deductive ways when faced with everyday mysteries. Unfortunately, mundane occurrences are not all the duo stumbles across. As they go through their school days trying to avoid drawing attention to themselves, Kobato and Osanai at times get caught up in incidents that put their plan of a peaceful, average life at risk.

One day, Hitoyoshi Yokoya wakes up to a mysterious nameless girl dressed as a maid ringing his doorbell, asking to be his servant. With her former master referring her to the Yokoya household, she offers her expertise as an assassin. Intimidated by her background, Hitoyoshi tries to send her away; but when she leaves something behind, he rushes to return it to her and is nearly hit by a truck in the process. With her fast reflexes, the girl saves him just in time, and Hitoyoshi ends up taking her in. Ironically, the maid lacks any skills apart from the art of killing she has perfected since childhood. Nevertheless, Hitoyoshi welcomes the girl with open arms, encouraging her to leave her monochromatic past behind and experience a normal life. To seal the deal, Hitoyoshi names her Yuki, marking the beginning of her path to redemption and happiness.

Rikuo Uozumi has all but resigned himself to a bleak future, aimlessly working at a convenience store in Tokyo after graduating from college. His monotonous life is interrupted when the peculiar Haru Nonaka makes a lively appearance, frequently dropping by his workplace to befriend him. When Rikuo learns that an old college friend and crush, Shinako Morinome, has moved back into town, he reaches out to further their relationship. Unbeknownst to Rikuo however, Shinako is carrying painful memories from her past that were holding her back from accepting his feelings. Meanwhile, as Haru continually opens up to Rikuo, he discovers that she, much like him, is living by herself and wants to step out of her comfort zone into an uncertain future. The past lingers long in the mind, and the future remains elusive. At a crossroads along their intertwined paths, these three experience what it means to let go of their feelings of yesterday and embrace the change that tomorrow brings.

As the commander of the Imperial Army's Third Legion, the Royal Empire's princess has led humanity to countless victories against the demonic Hellhorde. However, she has now been captured by the enemy and confined to the dungeons, with her sentient sword, Ex, as her only company. Due to her royal status, the princess knows invaluable secrets that would help the Hellhorde achieve dominance. To have her reveal all the information they need, the demons do not hesitate to subject the princess to the most vile forms of torture—that is, tempting her with delicious food, lasting friendships, adorable animals, and the most enjoyable experiences imaginable.