Higata Akio

Higata Akio (干潟彰夫) is a college student, appearing in Shinyaku Toaru Majutsu no Index Volume 13.

Personality
Of the three that chased after the Liquid Diamond, Akio is the most hesitant of it, conscientious of what they were doing. Despite this he clearly cared about his friends, wanting to help Ayumu after he was injured and prevented Shouji from attacking Akikawa Mie so that he won't become a murderer.

Magic God Invasion Arc
After High Priest threw a building which was saved Misaka Mikoto's electromagnetic powers, he and the others enter the building to steal the Liquid Diamond. Akio notes that this was at first a joke born out of their frustrations. They find Akikawa Mie retrieving it from the destroyed vault and begin chasing her.

After stealing a gun and P-Phone from a wrecked Anti-Skill vehicle destroyed during the High Priest's rampage, he, Kenzan Shouji and Okada Ayumu narrow down Mie's location. Now the joke has spiralled into something serious as Shouji is determined to obtain the Liquid Diamond. Akio mulls on what they were doing in chasing down a middle schooler and if he was prepared to save her. Shouji notices Akio's hesitation and confronts him, asking if there is a problem, to which Akio reluctantly says that there isn't, knowing that Shouji has the gun.

They eventually catch up to Mie, and try to take the Liquid Diamond from her. Unfortunately for them Kamijou Touma was nearby, and seeing her plight, decides to save her despite being chased by the High Priest. Touma plows the Acrobike into Shouji, allowing Mie to take back the Liquid Diamond container. Touma tells Mie to hold on to the container and get down as he pedals away. Immediately afterwards the High Priest passes through, still trying to catch up to Touma. This allows Mie to escape with the Liquid Diamond.

In the end, Ayumu was the one only who was injured by the High Priest. He is alive and conscious, but Akio fears that he might have broken something as he could not get up. Akio insists on getting help but is overruled by Shouji, whose greed has now consumed him. He threatens Akio with a gun, forcing him to continue in chasing down the Liquid Diamond with him.

Later, as the High Priest was attempting to destroy the foundations of Academy City, Shouji and Akio finally tracked down Mie. Despite being in a crowd with Judgment roaming about, Shouji points a gun at Mie, demanding her to give the Liquid Diamond to him. With his finger on the trigger, Akio hits him with a metal pipe. This distracts Shouji long enough for Mie's father and Shiosai, the man whose gun they stole, to knock him out. Shiosai then cuffs him. Mie asks why he attacked Shouji afterwards, to which Akio says that it was a better alternative than him becoming a murderer.

Quotes

 * (To Akikawa Mie, from NT12): "This is for the best... If he would have become a murderer otherwise, then this is for the best. We’re friends after all."