An animated short for the Arknights smartphone game's 1-year anniversary.

In the kingdom of Forland, a coup d'etat occurs which leads to the death of the King. In the last moments of his life, the King sends his second child, Princess Alita Forland to escape. Unfortunately, while fleeing, a life and death situation between Alita and the bloodthirsty bounty hunter Falis causes the two of them to switch bodies. Desperate for the safety of her Kingdom, Alita begs Falis to return and protect the Kingdom, offering herself as collateral. After a swift beating on the rebel forces, Falis resumes the title of Princess of Forland, leading to the birth of the most savage princess in their land, the "Murder Princess."

Although traumatized by witnessing the murder of his parents by one of the Choushuu, Ichimura Tetsunosuke's thirst for revenge lead him to desire strength. At the age of 15, Tetsunosuke approached the Shinsengumi, wanting to become one of its members. However, Tetsunosuke lacked the skill, mind and will to emotionlessly cut down whoever threatened peace and the Shinsengumi. Even with the support of his brother Tatsunosuke and his newfound friends of the Shinsengumi, little did Tetsunosuke know the blood and pain he would have to face being part of this historical group.

After his first appearance on the competitive world stage, Haruka is held captive by the swimming of the unmistakable champion, Albert, and feels like he's lost his way. With the current state of things, his swimming and what the water means to him are called into question. Haruka begins to sink to the bottom of the murky water as he struggles on his own. Pushed on by a restless urge in his heart, Haruka purposefully puts himself through a rigorous and intensive training regiment, relentlessly devoting himself to practice. In his heart, Haruka knows that he's pushing himself beyond his limits both physically and mentally. His friends can do nothing but watch over and have faith in him. Memories of Albert's cold, dry swimming keep replaying in his mind. I have to get faster, I have to become stronger. I have to compete against Albert again. Haruka unleashes his stroke to cut through the heavy, indifferent water. His friends draw closer to watch. What scenery will Haruka see at the end of this struggle＊──!