Fifth season of Strike the Blood.

In order to keep ocean peace, PKN was organized. It consisted of the state-of-the-art battle ships of various countries. However, they were raided during the foundation ceremony by the unidentified organization, USR, which plotted to conquer the world. They couldn’t be much for the submarine UX which was operated by Admiral Red of USR. But an old Japanese submarine, the 707 saved them, which was operated Captain Hayami at the risk of his life. One year later, succeeding to the 707, which had been ruined during the former fight, newly developed submarine, the 707 II, went for a sail. Among the crews, there were boys, such as Kenji, Goro, and Senta, who had been trainees. PKN formed a fleet led by the Great Guardian, which was the latest battle ship of the United States. However, the attacks of Submarine U were very server, and the fleet was defeated. Then, the 707 arrived. As soon as Red noticed the 707, he was glad to reunion with his rival and began to fight. Escaping from the submarine attack, they hid the 707 in the valley. But Red tried to destroy the valley in order to put the 707 into the torrents of mud. The 707 nearly escaped from it and got in the crater. However it was the pure water layer where the submarine couldn’t float up. At the moment, numerous torpedoes launched to the 707. (Source: AnimeNfo)

One day in the bustling city of Shibuya, a boy named Neku Sakuraba finds himself holding two black pins that enable him to read the minds of people around him. However, these pins also give him the ability to see the Noise, hostile creatures capable of erasing people from existence. After discovering that he is trapped within the confines of the city, Neku receives a message regarding a mission that will nevertheless erase him should he fail. While trying to fend off a Noise attack, Neku meets a girl named Shiki Misaki who asks him to form a partnership pact with her to fight against the monsters. Shiki explains that she and Neku have become Players participating in the Reaper's Game—an event spanning over seven days, each featuring a different mission. As Neku and Shiki both strive to survive each day that passes, they begin to meet other Players and Reapers alike, battle stronger Noise, and learn the truth behind the mystery that this game is shrouded in.

In the year 1939, humanity was on the verge of destruction. Equipped with weapons of devastating power, a mysterious alien race, known as the Neuroi, began an invasion of the Earth, ravaging the planet, obliterating countries, and vanquishing human armies. To counter this seemingly unstoppable force, the world's powers united. A new device was produced, called the Striker Unit, capable of facing Neuroi technology. Girls equipped with the Striker Unit became known as the Witches, forming humanity's last line of defense. They began their fight against the Neuroi, utilizing their now-enhanced magical abilities, flaunting destructive weapons no human could manage. Fast forward to 1944—Yoshika Miyafuji is a young teenage girl who eventually decides to join the 501st Joint Fighter Wing, known as the Strike Witches. With no formal training however, can Miyafuji learn to cooperate with her fellow Strike Witches? And if so, can she save humanity from the Neuroi onslaught?