Toujou Household
Basara Toujou[]
Basara is Jin's only son, so he loves him and would sacrifice anything for him by choosing to abandon his duties as a Hero. Jin considers Basara a real man capable of taking care of his two sisters all by himself, meaning that he has great confidence in him.
Mio Naruse[]
Jin knows and sympathizes with Mio's situation, so that's why he decided to take care of her under the guise of being her stepfather and entrusted her to Basara.
Maria Naruse[]
Jin took care of Maria under the guise of being her stepfather and entrusted her to Basara.
Shiba Kyouichi[]
Jin and Shiba don't interact with each other much throughout the series. However, it is known that they have one exchange while Basara was still an infant. This is where Shiba informs Jin that he's his clone that was created by the Vatican. Much to Shiba's surprise, Jin was already aware of that truth. Rather than getting upset with Shiba, Jin turns his attention to both the Vatican and the Elders. He was upset with the Vatican for going to an extreme in order to replicate his strength, but he was also upset with the Elders since they used Shiba as a path to political expedience for the Village. Ultimately, Jin decides against acting on his anger, realizing that he would endanger the life of Basara. Before parting ways with Shiba, Jin asks Shiba what he plans to do and that he would respond accordingly.
The only other instance where Jin gets to "interact" with Shiba is during his confrontation with Albareos. Albareos sends 7 Shiba clones to attack Jin, but Jin uses Banishing Shift to erase all traces of them. After dealing with Albareos, Jin causes an earthquake and destroys the cloning facility, preventing additional clones of himself from being created again.
Hero Clan
Shuuya Nonaka[]
Both Jin and Shuuya are close friends and comrades who fought in the Great War together, having great trust in him realizing the reason why he never informed him about the identity of Shiba Kyouichi.
Kaoru Nonaka[]
Like Shuuyu, Kaoru is close friends and comrades who fought, having great trust in her realizing the reason why she never informed him about the identity of Shiba Kyouichi.
The Elders[]
Though Jin followed the orders of the Elders in the past, he realized they would do whatever it takes to maintain their political status, knowing they would hesitate to use an infant Basara as a hostage if Jin had gone against the Vatican for creating Shiba.
Albareos[]
Albareos and Jin are former comrades. In the past, they were friendly with each other to the point where he used to take Jin to a certain restaurant whenever he visited the Vatican. Albareos often used to tell Jin about his plans for the future and how he wanted to make the world a better place while elevating the standing of the Hero Clan.
However, in the 20 years following the Great War, the two friends would go down drastically different paths. Albareos would ascend the ladder of power in the Vatican and eventually become the holy king. From that point on he would simply take action to further secure and maintain his power. He even started to consider the idea that Jin might one day become an obstacle with regard to being able to hold onto his throne. Jin, on the other hand, came back from the war with a son and decided to leave the Hero Clan on his own terms.
In volume XI's epilogue, the two would meet for the first time in 20 years. During their meeting, Albareos put his arrogance and bravado on full display for Jin. Uesu leaves open the possibility that Albareos might resent Jin for failing to make use of his power and moniker as a war god. Nothing was off-limits for Albareos. He would even go as far as making fun of Jin's decision to leave the Hero Clan and raise Basara. From Albareos perspective, Jin is unable to understand his point of view, seeing as Jin doesn't view the world from a seat of power.
Demon Realm
Wilbert[]
Both Jin and Wilbert had become close to one another establishing a pace between the Heroes and Demons due to his relationship with his younger sister. Even under the guise of Ramusas, he still maintained the same level of relationship with one another.
Sapphire[]
Jin and Sapphire develop a level of respect for one another during their several fights with each other in the Great War, which later soon progress into love after she was trapped in a dimension where Fafnir resided in, then assisted Raphaeline in saving him.
Sheila[]
Leohart[]
Though Leohart had some intent to use Mio to attain Wilbert's power, Jin is shown to be impressed with the skills of the current Demon Lord and even realized that he wasn't where the "rot" in the Demon Realm resided.
Divine Realm
Raphaeline[]
Both Jin and Raphaeline haven't had much interaction with one another aside from the latter coming into contact with him to give him Balmung to wield in the Great War. Despite this, after getting heated in his long fight against Sapphire, he still didn't hesitate to attack her after Raphaeline intervened resulting in a three-way clash, causing the three to be trapped inside of another dimension. After the three stopped fighting, Jin began to get rather close to Raphaeline in their attempt to get out, and he didn't hesitate to push both her and Sapphire after killing Fafnir and causing a tear to be opened.
After both goddess and demoness worked together to release Jin from the dimension where the other 20 Fafnirs remained, the three shared an intimate moment with one another, which resulted in Sapphire becoming pregnant. In order to ensure nothing would happen to the child, Raphaeline decided to take the child into her womb to have him in the Divine World despite knowing the consequences. After hearing what happened to her from Afureia, he didn't hesitate to decide to go into the Divine World and save her, but he was stopped after hearing her final request.
Other Gods[]
Jin's relationship to the gods is unknown, but he starts to have a strong grudge against members of the Ten Gods for what they did to Raphaeline after hearing that he plan to go to Divine Realm to save her. However, after hearing Raphaeline's last wish to bring peace between Hero clan and Demons, Jin respects her wish and postponed this matter for later. After he fulfills her wish, Jin immediately goes to Divine Realm for her, starting his war with the Gods.