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)

In a research facility hidden away on a remote island, genius programmer Shiki Magata has lived as a recluse for years. She rarely sees guests, but associate professor Souhei Saikawa and university student Moe Nishinosono still seek her out. However, their meeting is cut short when they are caught up in a locked-room murder mystery. Everything is not as it seems, and many secrets are hidden. Within an isolated facility, a seemingly impossible and gruesome crime takes place, and Saikawa and Moe must unravel the truth behind the murder and Magata's shrouded past.

Following Natsuki Enomoto's confession rehearsals with Yuu Setoguchi, their younger siblings Kotarou and Hina struggle to confess their own love. Despite a disastrous first meeting in middle school with her upperclassman Koyuki Ayase, Hina’s heart is captured by his warm smile. Initially confused by these newfound feelings, Hina soon realizes that she has fallen in love for the very first time. Chasing after her brother Yuu and her crush Koyuki, Hina also enrolls in Sakuragaoka High School; but the threads of love are far-reaching, and they entangle Hina and her friends. Boisterous but sensitive, Hina hopes to confess her feelings to the tender-hearted Koyuki. Meanwhile, Kotarou, oblivious to his own feelings for her, is determined to always keep Hina smiling. Suki ni Naru Sono Shunkan wo.: Kokuhaku Jikkou linkai follows Hina, Kotarou, and Koyuki in high school. Their youthful love forges new relationships, but also threatens to break others.

The final battle against the Dark Territory drags on, as players from all over the world flood the Underworld's servers and plunge the Human Empire into utter chaos. Asuna Yuuki and her friends defend their new allies with everything they have, but their numbers are falling. Meanwhile, Alice Zuberg heads toward the World's End Altar while Gabriel Vecta Miller relentlessly pursues her. Meanwhile, members of Rath strategize a plan in an attempt to restore Kirito's damaged fluctlight. However, the intruders occupying the main control room have other plans. Surrounded by death and despair, when all hope seems to be lost, one voice reaches out to Kirito—a familiar one saying, I will always be by your side. Sword Art Online: Alicization - War of Underworld 2nd Season is the epic conclusion to Akihiko Kayaba's dream of creating artificial human intelligence. Now it is up to Kirito and his friends to protect this collapsing world from the people that still think it is just a game.