After being recognized by the Iwagakure chief, Gabimaru was given the privilege of marrying the chief's daughter, Yui. Upon having her in his life, Gabimaru fell in love with Yui's kind and gentle nature towards him that he was never given in Iwagakure. Yui opened up Gabimaru's eyes in believing that he is not truly a heartless human being inside and that emotions will make him become strong. Gabimaru's feelings for Yui causes him to feel nervous when around her since he does not know how to act when compared to his casual demeanor around others. Yui's influence had an effect on Gabimaru's missions, as he started spare the lives of his targets rather than killing them in cold blood unless any of them were to threaten to target her. Having favored married life with her, Gabimaru came to the chief in hopes that he can abandon his life as a shinobi and live in peace with Yui.
After the betrayal at the hands of his village and given a second chance at redemption by taking on a mission given by the shogun, Gabimaru gladly accepted in hoping that he could see his wife again. Upon his travels to Kotaku, Gabimaru wasted no time in finding the elixir, was willing to face the dangerous members of Lord Tensen, and lose his humanity to the effects of Plant Tao in order to be done with the mission and return to Yui. He was also confident that Yuzuriha was wrong in her theory that Yui was an illusion based on his emotions.
When they first met, Sagiri acted as a reporter that took notes of Gabimaru's history during his time serving Iwagakure. She later revealed herself as a Yamada Asaemon and once Gabimaru accepted her offer to acquire the Elixir of Life for the shogun, Sagiri served as Gabimaru's executioner and made it her top priority to keep watch over him and made it crystal clear that she was not his ally. Gabimaru accepted this as long he could continue on with the mission.
After learning of the possibility of Iwa ninja being involved in the mission, Gabimaru tried to kill Sagiri so she would not weigh him down, however, he could not bring himself to do it after being reminded of Yui's words imprinted to him. He then becomes conflicted with himself since he believes that he will not be able to survive the mission without letting go of his emotions but is told by Sagiri that having emotions will make him stronger, similar to the same words his wife gave him. Having seen this side of Gabimaru, realizing that he is not heartless as others make him out to be, Sagiri tells him that she is willing to be by his side on his path to redemption if he were to hold on to his emotions while adding that he is no longer his former self. From then on, Gabimaru became grateful to Sagiri for helping him find his resolve and took her well-being into consideration after he subconsciously saved her from a Sōshin. Gradually their relationship with each other started to grow to where they can now have a decent conversation and fight alongside each other as if they were allies, but nevertheless, Sagiri still had to perform her duties as his monitor at all times. Knowing that he grew up in a terrible environment, Sagiri felt pity for Gabimaru and hoped in her heart that he would gain the pardon to be with his wife. After learning from Mu Dan that the Elixir of Life did not exist and hearing Yuzuriha's theory about Yui not existing, Sagiri went into a state of panic for Gabimaru's situation.
After reuniting with Gabimaru, Sagiri no longer saw him as nothing more than a mere criminal to keep watch over and smiled admitting to him, while suffering from amnesia, that she is his friend and tried helping him regain his memories so he can return back to his wife. Sagiri did note that their relationship was not so much mellow. Having decided to work together in escaping the island along with the other survivors, Gabimaru and Sagiri abandoned their roles as criminal and monitor and became true allies. However, Gabimaru did not forget that in order to receive his pardon he would have to return with his assigned Yamada Asaemon along with the elixir. Once the two separated after infiltrating Hōrai, Gabimaru used his Tao sensory to check to see if Sagiri was okay and quickly rushed to her location. He eventually reunited with her once again and sees her panicking over his condition due to Zhu Jin disrupting his Tao but moved on to ask if she was doing okay. Though this felt like a selfless act of concern to her, Sagiri realized she had gotten the wrong idea after Gabimaru reminded her of the requirements of the mission, much to her disappointment.
When they first met, Yuzuriha recognized Gabimaru right away based on the description of his famous reputation in the ninja villages but was unimpressed with his capture. Later, the two reunited on Kotaku after she helped save Gabimaru from a Sōshin. Gabimaru was grateful for this deed but wanted to know why she did it. Yuzuriha requested to form an alliance with Gabimaru to help better their chances at survival. Knowing how kunoichi operate, along with the fact that she is only looking out for herself, Gabimaru was reluctant to cooperate with Yuzruiha at first but agreed to the team up knowing that she is reliable. As per their agreement, Yuzuriha offers the information she gathered on the island while Gabimaru handles the responsibility of fighting any enemies they encounter. After they encountered Rokurōta, Gabimaru asked for Yuzuriha's help in fighting him but was turned down after Yuzuriha happily use their agreement to pull one over on him.
After Gabimaru separated from the group, Yuzuriha had little concern for his well-being since she was not on board with finding him. It was only thanks to Hōko's offer to guide the group through Hōjō's thick mist that she was willing to go look for him. Despite this, Yuzuriha did show concern for Gabimaru's injuries after his fight Aza Chōbē. After the survivors agreed to work with each other, Gabimaru came to terms with Yuzuriha in wanting to look after herself and had a mutual understanding since his top priority is keeping himself alive to return to Yui. At any rate, Gabimaru displayed exception teamwork with Yuzuriha in their fight against Ran and made her developed a change of heart after they were left badly injured. Instead of fleeing by herself, Yuzuriha chose to take Gabimaru with her as she attempted to escape from Ran. She also made the decision to fight alongside him despite her injuries and was willing to use up her last remaining Tao she had left to defeat Ran. Once the battle was over, Yuzuriha told Gabimaru to go to the Rentan Temple without her, but before he agreed to leave, Gabimaru whole heartily thanked Yuzuriha once again for saving his life from when they first met on the island.
Upon teaming up with Yuzuriha, Gabimaru also cooperated with her Asaemon, Yamada Asaemon Senta. Gabimaru had no problem talking casually to Senta and to discuss matters.
Upon teaming up with Yuzuriha, Gabimaru also cooperated with the second Asaemon monitoring her, Yamada Asaemon Genji.
Mei is a young girl from Kotaku and has become an ally of Gabimaru and the other survivors. The two got off to a bad start after Gabimaru had her tied to a tree and became intimidating, causing her to cry in fear. His bad impression continued after he pointed his sword at Mei to see if she could regenerate like Hōko. It was only after Gabimaru showed politeness to her when she exposed her scar that Mei saw him in a new light.
Upon making a quick haste to Hōrai, Gabimaru was unknowingly followed by Mei and was saved by her after coming close to death with Zhu Jin. Gabimaru became very grateful to Mei afterwards and was willing to go out of his way to repay her in any way. After encountering two Dōshi who came to take Mei back to Hōrai, Gabimaru could not allow himself to see this through after seeing her in tears and rushed to her side to protect her. Gabimaru then refused to have her be taken by them and also became infuriated after the Dōshi revealed their intentions of using Mei to engage in Bōchū Jutsu and how they viewed her as an object after stating that her scar meant that she was marked.
Since she witnessed how Gabimaru was willing to protect her from her enemies, Mei saw him as someone she can trust and helped him unlock his ability to use Tao. Mei cares greatly for Gabimaru's well being. After he regained consciousness from using Tao, Mei worried for Gabimaru's condition since his Tao had not fully formed. Mei also tried to stop Gabimaru from losing his life during his fight with Chōbē.
After regaining his memories back, Gabimaru hears Mei's wishes in wanting to meet Rien and Xu Fu one more time before leaving the island to start a new life. Having been indebted to her for saving his life twice, Gabimaru swore to Mei that he would see to it that this would happen when the time came for the survives to invade Hōrai.
Hōko was a native to Kotaku and was willing to help Gabimaru and his group with their mission by providing them with lodging and information on the island. The reason for his assistance being is that he wishes to honor the requests of those who would eventually meet their end by Lord Tensen but did not want to get involved with any of their affairs onward. However, after noticing that Mei has left to follow Gabimaru to Hōrai, Hōko was willing to guide Gabimaru's group and help to defeat Mu Dan.
Tamiya Gantetsusai is one of the criminals Gabimaru is competing with to earn the shogun's pardon. The two first encountered each other in Hōjō where they prepared to fight. Gabimaru instead changes his mind in requesting an alliance with him and Fuchi in order to win against Lord Tensen. Gantetsusai becomes reluctant to join forces with him because of how he views Gabimaru's request as being cowardly