Okahira is a tall, heavily-built man with broad shoulders. He keeps his black hair slicked back from his face, which has prominent eyebrows and large, wide eyes. His nose and chin are also quite prominent, giving his face a wide and flattened appearance.
Little is known about his personality, though he is critical of Furuta's perceived cowardice and weaknesses.
Okahira stood behind Ihei when she fought against Matsumae, and gave her T-Human when the situation seemed bleak. After Ihei and Shiki Kijima's death, Okahira assumed leadership amongst the three remaining investigators, ordering Furuta to stand by behind him. Furuta, however, held him in place as a meat shield, seemingly killing him in the process while saying that he "stood by behind him" as asked.
In the aftermath of the operation, he was among the investigators taken by Aogiri.
Confronted and threatened by Kurona Yasuhisa, Akihiro Kanou released Okahira from a capsule and pitted his creations against one another. They briefly fought, but Kurona outwitted him and burned him with the steam from a slashed pipe. After stabbing him through the stomach with her kagune, she left him for dead. 
However, he soon recovered from his wounds and ambushed her from behind. Okahira apologized to her, explaining that he and the other experiments did not have any choice in their actions. He then twisted her head around, breaking her neck. While this failed to kill her, it forced Kurona to flee to the ceiling to regroup and allowed Nishiki Nishio to ambush Kanou in the chaos. 
Some time following the Clown Siege, Okahira was approached by Koori Ui in a park. He warned him that despite Koori's hopes for the dead to "live" once again, they do not truly return. Afterwards, Okahira left Koori to take a medicine that was keeping him alive.
Under the establishment of the TSC, he and his companions continued to use the stabilizers stolen from Kanou and supported the TSC until their lives expired.
Power and Abilities
Quinx Physiology: After being turned into a Quinx, Okahira possesses higher physical capabilities with a kakugan manifested in his left eye along with an unknown kagune.
Ukaku Kagune: Though not the case in the manga, in the Tokyo ghoul:re anime it's shown that the Quinx experiments Kanou unleashed on kurona were labeled as "owls" in their containment vats implying they all got Kakuhou transplants from kuzen .