Since he was a child, Ryuuichi Naruhodou's dream was to become a defense attorney, protecting the innocent when no one else would. However, when the rookie lawyer finally takes on his first case under the guidance of his mentor Chihiro Ayasato, he realizes that the courtroom is a battlefield. In these fast paced trials, Ryuuichi is forced to think outside the box to uncover the truth of the crimes that have taken place in order to prove the innocence of his clients. Gyakuten Saiban: Sono Shinjitsu, Igi Ari! follows Ryuuichi as he tackles cases to absolve the falsely accused of the charges they face. It will not be easy—standing in his path is the ruthless Reiji Mitsurugi, a prosecutor who will stop at nothing to hand out guilty verdicts. With his back against the wall, the defense attorney must carefully examine both evidence and witness testimony, sifting through lies to solve the mystery behind each case. With a shout of objection!, the battle in the courtroom begins!

In the near future when technology has significantly advanced, a famous AI TV fortune teller seemingly foresees high school student Asahi Kashiwagi's day with pinpoint accuracy. On his way to school, he encounters Aoi Izumisawa, Bai Mongfa, Karin Istel, Amelia Irving, and Ilya Ilyukhin. Despite meeting them for the first time, Asahi suddenly receives love confessions from all of them at the end of the same day, perfectly aligning with the fortune teller's prediction. As if that was not enough, Asahi soon learns that these five individuals are actually candidates to become his bride, and they have been invited by his father to live at Asahi's home. Left with no other choice, he reluctantly allows them to stay, resulting in a bawdy turn of events that brightens up his average high school life. However, as Asahi spends more time with them, forgotten memories gradually resurface. While uncovering the hidden truth, Asahi begins to believe that his fate with these potential partners might be more than just mere coincidence.

Average student Mitsuki Mutou suddenly finds himself transported to another realm. Summoned by the king of this world for the remarkable power he is supposed to possess, Mitsuki is thrown out when it appears that he lacks a Special Concept. Moping about, he encounters a priestess named Menou who explains that Japanese people like him are known as Lost Ones, and such individuals never fail to have Special Concepts. Menou elaborates that she is part of a church that helps abandoned Lost Ones integrate into society. She invites him to spend the night at her church, where the two can probe the nature of his ability. Eventually, they discover that Mitsuki's Special Concept is actually incredibly powerful and dangerous. But is Menou's true goal to assist Lost Ones—or the opposite?

A new Holy Grail War is emerging in Snowfield, Nevada, where mages from around the world summon Servants, heroic spirits drawn from myth and history, to fight on their behalf. However, this war seems to differ from previous ones. The organization behind it appears to have used data from the Fuyuki Grail War for their ritual, resulting in strange happenings. Unbeknownst to most participants, this budding conflict is actually a fake Grail War. There exists another set of seven true Servants who are summoned to fight in the genuine Holy Grail War. One of these Servants is a powerful Saber-class who saves the life of Ayaka Sajou, his apparent master, after being summoned. With hidden agendas and unpredictable forces at play, the line between the fake and true Grail War becomes unclear, turning Snowfield into a dangerous battlefield.