ข้อมูลอนิเมะA Certain Magical Index II

Following the fake boyfriend incident with Mikoto, Tōma still hasn't finished his summer homework and Index isn't helping much. Whilst Tōma takes Index to a restaurant for a change of location, they are attacked by magician named Ouma Yamisaka who kidnaps Index and runs off. As Tōma tries to find her, running into Mikoto along the way, Ouma prepares a ceremony that will allow him to access the grimoires inside Index's head in order to find a cure for a curse inflicted on a woman he has fallen in love with. As the ceremony begins, Ouma's body and mind is put through excruciating pain trying to access the grimoires. Thanks to Index using her new cellphone, Tōma is able to find her and stop the ceremony. Tōma gets Ouma to snap out his pitiful state and offers to cure the woman's curse using his Imagine Breaker. Meanwhile, Kanzaki is seen fighting the Knights of England.

Archbishop Laura informs Stiyl that the Liber AL vel Legis has been stolen by the Amakusa Catholics and sends him to Japan along with a group of Catholic battle nuns known as the Agnese Forces, to search for the grimoire and Orsola Aquinas, the only one who can decode it who was also kidnapped by the Amakusas. In order to get Tōma's assistance, Stiyl pretends to kidnap Index. While Tōma coincidentally runs into Orsola on the way to save Index, the Amakusas appear and abduct her via a hole in the ground. After determining that the Amakusa's goal is to use a special teleport magic to escape with Orsola before midnight, Tōma, Index, Stiyl and the Agnese Forces set up camp at the required location, where Tōma gets into a lot of awkward situations with the group's leader, Agnese Sanctis. Because Kaori was once an Amakusa Catholic, Stiyl knows he may have to fight her if necessary. Meanwhile, the Amakusas prepare to make their move.

The Agnese Forces face off against the Amakusas as a diversion while Tōma, Stiyl and Index sneak inside the amusement park. While escaping from some Amakusa warriors, Tōma manages to find Orsola and gives her a crucifix that Styil gave him earlier. The two are reunited with Stiyl and Index, who are facing against the leader of the Amakusas, Saiji Tatemiya. Working together, Tōma and Stiyl defeat Saiji and the rest of the Amakusas are captured by Agnese's battle nuns. However, the captured Saiji reveals to Tōma and Index that the Amakusas have never stolen the Liber AL vel Legis, as the real reason the Catholic Church wanted Orsola was to kill her to prevent the secrets of the grimoire from being abused. The Amakusas only got involved as Orsola sought them for protection but ran away as she didn't trust them. Troubled by this revelation, Tōma asks two of the Battle Nuns, Luccia and Angelene to see Orsola again but he accidentally angers Luccia who tries to kill him, Index and Saiji. However, she and Angelene are forced to retreat when Index uses spell interception on Angelene's magic and counters Luccia's attack.

Stiyl explains that the Catholics won't kill Orsola until they can prove her to be a heretic. As Saiji leaves to free his comrades, Stiyl tells Tōma and Index to go home, since they have no further stake in this matter. Tōma, however, goes by himself to where Orsola is being held and tortured by Agnese's battle nuns, who reveal they deceived Necessarius to assist them. He is later joined by Stiyl, who reveals the crucifix Tōma gave to Orsola means she is under protection of the Church of England, followed by Index and the Amasukas. Whilst Tōma is put in charge in protecting Orsola, the others fend off the battle nuns, with Index utilizing the power "Sheol Fear", to deafen and paralyze some of the battle nuns. However, Luccia brings another force of battle nuns who willingly stab their ears to protect themselves from Sheol Fear.

As Tōma, Index, Stiyl, Saiji and Orsola barricade themselves from the battle nuns, Tōma and Index come up with an idea that Orsola could help them decipher the Liber AL vel Legis in Index's head to their advantage. When Orsola mentions her deciphering method, Index reveals her translations is a fake, revealing Orsola was never able to really decode the grimoire all along. Whilst the others fend off against the battle nuns, Tōma confronts Agnese who attacks him with her Lotus Wand. However, Tōma manages to learn its attack patterns and land a hit on Agnese. As Agnese tries to bluff that Tōma sacrificed his friends as decoys, they arrive with Innocentius, who Stiyl managed to summon thanks to the Amasukas. Her confidence broken, Agnese is knocked out by Tōma, breaking the battle nuns morale, before Tōma himself falls unconscious. Waking up in a hospital in Academy City, Tōma is greeted and taken care by Kaori, who thanks him for helping and tells him that Orsola and the Amasukas are now under the protection of the Church of England. Meanwhile, back in London, Laura reveals to Stiyl that the true reason she got involved with the Orsola incident was to get the Amakusa Catholics under her control and use them as leverage to ensure Kaori's loyalty to Necessarius.

Kuroko's day of shopping with Mikoto is interrupted by reports of robbers stealing an aerospace carrycase. Kuroko subdues the thieves but is then attacked and wounded by their leader, another teleporter named Awaki Musujime. She reveals to Kuroko about Tree Diagram's destruction and how various factions are gathering of its remnants, the contents of the carrycase being one of them. Kuroko manages to escape, but becomes concerned over what Awaki had told her, particularly concerning how Mikoto had been trying to stop them for reasons she had kept from her, (namely being that if Tree Diagram were rebuilt, the Level 6 Shift experiment would start over again). As Mikoto goes out that night to confront Awaki, Kuroko decides to follow her and overhears their conversation before Awaki escapes. As Kuroko decides to take matters into her own hands, Misaka 10032 decides to take action.

Kuroko finds Awaki at a nearby building and uses the latter's trauma of self-teleportion to make the first strike but during their battle, her injuries make her unable to concentrate on teleporting and she is trapped under a pile of furniture. Awaki explains to Kuroko that she and her organization, the Science Syndicate, plan to build a new Tree Diagram in order to create other species of espers. Awaki tries to persuade Kuroko to join her, believing her powers is a curse that caused her to become how she is. Kuroko rejects her offer, verbally abuses Awaki for making excuses for her own behavior, breaks loose and tries to attack Awaki, but is shot by her. After a brief traumatic loss of control over her powers, Awaki attempts to kill Kuroko by dropping the building on top of her, but she is saved by Mikoto and Tōma, who came to rescue her after he was alerted by Misaka 10032. As the Anti-Skill's stop the Science Syndicate, Awaki tries to escape but to her horror, is confronted by Accelerator who, using the Misaka Network to utilize his powers, defeats her and destroys the Tree Diagram remnant. As everyone recovers, Mikoto gives her thanks to Kuroko.

Academy City is hosting the Grand Champion Star Festival, a sports competition between the various schools of the city, during which visitors from outside the city are allowed entry. Whilst Tōma's parents, Tōya and Shiina, as well as Misuzu, a relative of Mikoto's, get to know each other, Tōma and Mikoto decide to make a bet in which the loser does anything the winner wants. Meanwhile, Laura contacts Aleister to inform him that magicians have infiltrated Academy City in order to make a transaction with a magical weapon called the Stab Sword, which has the power to kill a Saint. Meanwhile, Tōma has several troubles with a hungry Index and awkward situations with the class representative, Seiri Fukiyose. Later, Tōma runs into Stiyl and Tsuchimikado, who tell him about the intruding magicians and asks him not to get Index involved. Whilst getting scolded by Seiri after an awkward incident with Index and Komoe, Tōma runs into a woman named Oriana Thomson. When his Imagine Breaker reacts to her, he realizes she is one of the magicians in question and starts to follow her.

As Oriana realizes she's being followed and runs away, Tōma, Stiyl and Tsuchimikado chase her through a bus station filled with booby traps, but she manages to escape and uses a counter magic called Short Hand to avoid being traced. Despite Tōma's objections, Tsuchimikado and Stiyl undergo a painful magical spell in order to locate the Short Hand spell, which happens to be right in the center of a middle school ball throwing tournament. With the competitors in danger of being hurt by the spell if they touch it, Tōma and Tsuchimikado infiltrate the match as contestants in order to find it, only to find the opposing team is Mikoto's school. Tōma tries to protect Mikoto from one of the basket poles which he believes has the Short Hand, only for Seiri to end up touching the real one and gets hit by magic and falls unconscious before Tōma destroys the spell. As Seiri is taken to the hospital, Tōma vows to make Oriana pay on what she did.