The male and female protagonists were lovers in junior high school. The heroine's parents divorced and her mother, who was very good to her, was killed in a car accident. She became a mercenary for revenge and lied to the male protagonist that she was going to study abroad. They were separated for five years.
Five years later, when the male protagonist is in his senior year of high school, the female protagonist originally did not want to go back to the male protagonist, thinking that she would stay in the mercenary world to survive all her life. However, she later saw that the organization she belonged to was eyeing the male protagonist's special blood, so she had to defect and return to the male protagonist to protect him.
The two of them met many mercenaries one after another to chase them, similar to Demon Slayer: Kimetsu no Yaiba. Almost every one of them was a boss, and each one took a long time to fight.
Later, they formed a team with several other defectors. The male protagonist's senior year of high school life continued as usual, except that he added the plot of fighting with mercenaries (especially during the summer vacation and when he went to college, the battles were the most), and it was daily life when studying (the female protagonist also joined their class)
At first, the heroine thought that in the eyes of the hero five years ago, she was a scumbag who would never come back, so she wanted to pursue him again with a new identity. However, the hero kept saying that she liked someone, but did not say who it was, so the heroine thought that he liked someone else.
Just, chasing his wife in the crematorium, basically abusing the heroine all the time.
Later, one time the male protagonist deliberately broke the female protagonist's most beloved thing, and the female protagonist finally gave up chasing him, saying that she was tired.
Later, the male protagonist went to KTV to drink and sing with friends. After the female protagonist saw the male protagonist's diary, she knew the truth and went back to find him.
The two are back together.
After that, there are all kinds of sweetness, all kinds of abuse of life and death (supporting roles).
Intention: pure love