Ryūnosuke Akutagawa vs. Kyōka Izumi

Ryūnosuke Akutagawa vs. Kyōka Izumi is a battle fought between Port Mafia member Ryūnosuke Akutagawa and Armed Detective Agency member Kyōka Izumi during the cannibalistic mutual destruction operation.

It happened somewhere in the Mafia headquarters while Kyōka attempts to seek out from Ichiyō Higuchi the code on the safe room where the virus-afflicted Ōgai Mori had been relocated to.

Prologue
After the assassination attempt on Mori by Jun'ichirō Tanizaki has been thwarted by Kōyō Ozaki, the Mafia moves their boss to a secret safe room. Meanwhile, as the Agency has resolved to fight the Mafia head-on, Kyōka breaks in the Mafia headquarters to threaten Higuchi into spilling the boss' safe room passcode. Higuchi, restrained by Demon Snow, refuses to divulge the code, so Kyōka prepares to slice off her arm with her ability.

However, Akutagawa arrives and quickly slices off the ground on Kyōka. He instructs Higuchi to inform the higher-ups about the break-in, relishing how he finally gets to fight a worthy foe.

Battle
Kyōka and Akutagawa exchange quick successive attacks on each other with Demon Snow and Rashomon, respectively. Akutagawa then binds Demon Snow in Rashomon, remarking how transferring to the Agency does not suit her for degrading her assassination skills and strategy. Kyōka retorts that she is no longer the same person he once knew, afterwards turning Demon Snow incorporeal to escape its restraints. Akutagawa launches multiple tendrils at Demon Snow, but Demon Snow is unaffected by his physical attacks. He then activates Spatial Distortion to block Demon Snow's counterattack.

To his shock, Kyōka stealthily sneaks behind him with her tantō after using Demon Snow as a ruse. She then recalls how he once described her to be unfit for anything other than killing and imparts her goodbye to him. However, despite her speed, Akutagawa activates Tenma Tengai on his left hand and successfully grasps Kyōka's blade, resulting to a minor cut wound. He then destroys her weapon with his Rashomon-clad hand, forcing Kyōka to turn on the defense.

Aftermath
Akutagawa notices how Kyōka has changed since then, reminiscing how her eyes are different from when they first met. He recalls how she yearned to fight him six months ago to kill Demon Snow to avenge her parents and kill her afterwards, describing how her eyes were filled with revenge against life itself. Kyōka asks how he knows so, to which Akutagawa speaks of a man he knows who bore the same eyes as her and ended up just like Kyōka, when he once met someone, joined a group, and stopped yearning for death from then on.

Remembering Atsushi Nakajima's words on how he wishes to give value to Kyōka so she can live, Akutagawa tells Kyōka that he is glad for her, earning her surprise. Kyōka then retreats and flees from the site, while Akutagawa is contacted by Higuchi to take cover for Motojirō Kajii's upcoming Lemon Runway.

Manga and Anime Differences
In the manga, after Demon Snow escapes its restraints from Rashomon, Akutagawa attacks it with a barrage of attacks, but Demon Snow remains incorporeal and is unaffected by his physical attacks. This is altered in the anime, where Demon Snow turns intangible and reappears behind Akutagawa, after which he activates Spatial Distortion. Furthermore, their conversation after the battle is relatively shortened in the anime, omitting how Akutagawa cited the specific instances when Kyōka's eyes saw no value in her life and Akutagawa recalling Atsushi's words to him.

The manga depicts Kyōka fleeing the site after Akutagawa tells that he is glad for her, after which Higuchi notifies Akutagawa about the Lemon Runway. In the anime, Higuchi contacts Akutagawa about the Lemon Runway after their post-battle conversation, forcing Kyōka to retreat. In addition, Higuchi had to confirm Akutagawa's response, to which he acknowledges and leaves soon after.