Big Daddy Part 1 Edit
At the barricade across from Mach Bowl, Shun Akiyama sees a heavily pregnant woman, Kazumi, talking to a Self Defense Force (SDF) officer. Akiyama asks her if something is wrong and she explains that the SDF will not let her pass the barricade. Kazumi reveals that she was supposed to meet her boyfriend, Guy Kendo, in Theater Square the night before to reunite after his release from prison. However, with the SDF erecting barricades around Kamurocho, he is now stuck within the quarantine zone and she worries for his safety. Akiyama muses that Kendo has probably left the area but Kazumi is adamant that he is still there, describing him as "kind of a bonehead sometimes" but "as dependable as they come". She also tells Akiyama that Kendo ended up in prison because he took the fall for someone else . As Akiyama leaves Kazumi he thinks about checking Theater Square.
The next time Akiyama enters the quarantine zone and reaches Theater Square, a man runs up to him wanting to know why he is there. It is Kendo, still waiting for Kazumi in case she showed. Kendo is relieved to hear that Kazumi is safe. Akiyama helps Kendo to escape the quarantine zone, progressing through the Kamuro Theater, Theater Underground, and exiting via the Millennium Tower elevator.
Outside the Theater Square barricade, Kazumi and Kendo are reunited, and incredibly thankful to Akiyama. Kendo vows to return the favor by assisting Akiyama in the quarantine zone, citing his impending fatherhood as a reason to start setting a good example. Gary "Buster" Holmes suddenly appears behind the trio and tells Akiyama that he'll take Kendo for training, despite Akiyama's protestations. With that, Gary, Kendo, and Kazumi leave Akiyama.
Big Daddy Part 2 Edit
Akiyama visits Gary's Boot Camp to check in with Kendo. They head to the quarantine zone to practice working together. In the Millennium Tower basement they clear the area of zombies before returning to the safe zone.
Outside the Millennium Tower rear elevator the duo are met by Nomoto, a moneylender. Nomoto asks Kendo if he knows Akira Mitani; his debt repayment is overdue but Nomoto has been unable to reach him. Kendo doesn't know where Mitani is, having just left prison and not associating with him anymore. To Akiyama's surprise, and Kendo's annoyance, Nomoto reveals that Mitani is the man for whom Kendo went to prison. Mitani's debt is 2 million yen and Nomoto believes he will try and borrow money from Kendo.
When Nomoto leaves, Akiyama inquires about Kendo's imprisonment but is rebuffed. Kendo receives a phone call from Kazumi; Mitani showed up at her workplace on Nakamichi Street to shake her down for money. After the call, Kendo runs towards Nakamichi Street and Akiyama decides to follow.
Akiyama catches up with the couple at the south end of Nakamichi Street and sees bruising on Kazumi's face. She explains that Mitani was desperate for money but she declined to help and he hit her. Kazumi then called Nomoto to give him Mitani's whereabouts in order to get him to leave. Akiyama is confused as to why Mitani would ask Kazumi for money. With Kendo's support, she unveils that Mitani is the father of her baby.
Akiyama and Kendo go to Children's Park so Kendo can explain the situation: He and Kazumi grew up in the same town but she left for Tokyo straight after high school. Kendo had long had feelings for her but by the time he made it to Tokyo himself she was in a relationship with Mitani and pregnant. Kazumi, oblivious to Kendo's feelings, introduced him to Mitani, whom he took an immediate dislike to. Nevertheless, in order to be with Kazumi, Kendo began to socialise with her and Mitani.
One night, a drunk Mitani picked a fight with a man who he seriously injured. They had planned to walk away from the injured man as he too was drunk but a police officer showed up. Realising that Kazumi would be left to raise a child by herself if Mitani was imprisoned, Kendo claimed that he had committed the crime. While in prison, Mitani left Kazumi for another woman. When Kendo found out he proposed to Kazumi, who accepted.
Akiyama admits that he had judged Kendo wrongly and that he was a good man. At that moment Kendo receives a phone call from Mitani, who claims that Nomoto will kill him if caught. Akiyama is again awed by Kendo's good nature as Kendo states that he will help Mitani for Kazumi's sake; she would blame herself for his death if he was killed due to her revealing his location to Nomoto.
Akiyama and Kendo make their way to Shichifuku Parking Lot, only to find Nomoto instead of Mitani. Nomoto has lost track of Mitani but has people looking for him. Akiyama and Kendo surmise that he must have gone into the quarantine zone. Kendo proclaims that he will go after him and runs towards the Millennium Tower, leaving Akiyama with Nomoto.
Big Daddy Part 3 Edit
Inside the quarantine zone, Akiyama catches up with Kendo battling zombies by the entrance to the Theater Underground. They make their way up to the ground floor of the theater, stopping for a breather, when Mitani runs in from Theater Square. Mitani is shocked about the zombie situation and demands a gun from Kendo. Akiyama refuses him, causing Mitani to shout angrily and draw a group of zombies to their location. Mitani takes refuge in a corner while Akiyama and Kendo dispatch the zombies.
Back outside the Millennium Tower elevator, Kazumi is relieved to see Kendo unharmed. Mitani realises that they are in a relationship and demands a payoff for the baby. Akiyama argues that Mitani gave up his right to call himself the baby's father and that Kendo was now the father. As Mitani angrily demands to know who Akiyama is, Nomoto arrives and introduces Akiyama as being in the same line of work as himself. He calls Mitani an idiot for thinking he would be killed as that would leave Nomoto unable to reclaim what he is owed. Mitani falls to his knees, defeated.
Kendo and Kazumi thank Akiyama for helping them once again. Kendo offers help to Akiyama whenever needed and Kazumi gives him an Eye of the Dragon. Kazumi requests Akiyama keep an eye on Kendo for her before she and Kendo leave. Akiyama hopes that the experience straightened Mitani out so Kendo and Kazumi can get on with their lives.