Peaceful schoolgirl by day, fearsome monster slayer by night, Saya Kisaragi is leading a split life. Equipped with a ceremonial sword given to her by her father for sacred tasks, she vanquishes every monster who dares threaten her quiet little village. But all too soon, Saya's reality and everything she believes to be true is tested, when she overhears the monsters speak of a broken covenant—something she knows nothing about. And then, unexpectedly, a strange dog appears; it asks her to whom she promised to protect the village, curious as to what would happen if she were to break that promise. Tormented by unexplainable visions and her world unraveling around her, we travel with Saya through her struggle to find a way to the truth in a village where nothing is as it seems. [Written by MAL Rewrite]

Kaoru Hanabishi, a college student who lives alone, met a beautiful but bewildered girl dressed in a kimono at a train station. He volunteered to guide her way to the address she was looking for, which happened to be in his neighborhood, but turned out to be an empty lot. Not knowing what to do next, Kaoru invited the devastated girl to his apartment and asked for any additional clues to her destination. She supplied him with a photo of two children whom Kauru immediately identified as himself and Aoi Sakuraba, his childhood friend. It turned out that the girl in front of him is Aoi Sakuraba herself, his betrothed fiancee who came all the way to Tokyo to marry him. Her revelation was not only surprising but also reminded the deepest part of Kaoru's memory for why he left the Hanabishi family in the first place.

Two years after meeting Aoi, Kaoru and gang are still up to their normal habits. Kaoru now in grad school and the tenants being as rowdy as ever what will become of Aoi and Kaoru's love. Two years has passed since Aoi and Kaoru were freed from the bonds of their families. They continue to live their normal lives with their usual friends in their house.

Ren Mihashi was the ace of his middle school's baseball team, but due to his poor pitching, they could never win. Constant losses eventually lead to his teammates bullying him and reached the point where his teammates no longer tried to win, causing Mihashi to graduate with little self-esteem. As a result, Mihashi decides to go to a high school in a different prefecture where he has no intention of playing baseball. Unfortunately, upon his arrival at Nishiura High, he is dragged into joining their new team as the starting pitcher. Although unwilling at first, Mihashi realizes that this is a place where he will be accepted for who he is; with help from the catcher Takaya Abe, he starts to have more confidence in his own abilities. Abe, seeing the potential in Mihashi, makes it a goal to help him become a pitcher worthy of being called an ace. [Written by MAL Rewrite]