Keyaru treasured Anna as his first love, and regarded her as the only person who manages to keep a part of his sanity. The two grew up together in Alban village like they were siblings, with Anna treating Keyaru as his younger brother and the same time as a dear friend. When Keyaru's parents died, he remembered how Anna was always at his side, even offering him to live with her family and visiting him constantly.
In the light novel and manga, after Anna was raped by Renard, she committed suicide thinking he was Keyaru. In the anime however, Anna survives long enough to see the real Keyaru one last time before she passed away, smiling. When Keyaru learns of this event, he transmutes the captain into a woman (although he purposely left his genital unchanged), and has all of his men rape the captain to death. Afterwards, Kearu decides to have sex with Setsuna (and also Freia in the anime) while crying, showing that Keyaru does treasure her, and refers to Anna as his first love.
When Flare found out that Keyaru was just a healer and how he could even recover lost limbs, she drugged him and used him as a tool, sometimes for her own sadistic means. She was also the one who triggered the change in Keyaru's personality and was the first target of Keyaru's revenge. After acquiring enough strength to take revenge on her, he rapes her, erases her memory and slightly modifies her appearance to transform her into an ideal girl, while leaving her knowledge intact. He then turns her into his slave and convinces her they are lovers, referring to her as his 'toy'. During their adventures, they frequently engage in sexual intercourse. After Setsuna joins their party, Flare often gets jealous when he acts affectionate towards her. She now cares deeply about him and follows his every command.
After spending some time with her new persona, Freia, Keyaru realizes that she doesn't retain any of Flare's malevolence, and wonders if the environment at Jioral Kingdom turned Flare into who she was. Nevertheless at that time, he still thought of Freia only as a means to get his revenge on Flare; making her attack the Jioral Kingdom, fight against her armies and even against her father so he could restore her memories back and see how she would suffer. However, spending more time with Freia has caused him to contradict himself several times; thinking of her as a different person than Flare and constantly protecting her.
After escaping imprisonment, Keyaru buys her with the gold he acquired by selling the antidote to the citizens of Ranalita. She is initially hesitant to cooperate with him, but quickly develops a bond with Keyaru after engaging in sexual intercourse to increase her level cap. She is also referred to as a 'toy' by Keyaru and has developed a romantic relationship with him, similar to Flare. At difference of Freia, who has before princess Flare, Keyaru took a liking to Setsuna instantly, because she shared the same madness and rage that ignites their desires of revenge, so the two develop a bond fastly, with Keyaru finding joy in Setsuna as he makes his thorny road of revenge less solitary. Later, he admits that Setsuna is the first of his sexual partners which he falls in love.
On the other side, Keyaru also puts trust in Setsuna and is impressed with her raw talent, seeing how he polished her technique in order to overcome the limitations of her level and how she keep growing more stronger with his help. As a hand to hand combatant, she is able to help help to protect Freya and Ellen who aren't proficient in close range battles and to keep in check of any surprise attacks. However at the same time, he finds it amusing and somehow problematic about the little jealously acts of Setsuna and her friendly competition with Freia and the other girls.
When her arm was restored, Kureha reacts with genuine gratitude and promises to return the favor. After his escape, they meet again as enemies, but become allies as she is bested in combat and learns the true nature of the Jioral Kingdom. Due to the influence of an aphrodisiac used in battle, Kureha becomes intimately infatuated with Keyaru. This infatuation continues even after Kureha becomes the new Sword Hero, replacing the late Blade.
After defeating her with the power he claimed by healing the heroes in the first world, she says that she had something to protect and vanishes. After traveling back in time, he meets her in a tavern in Buranikka, though she wasn't made demon king yet. He coincidentally rescues her from a group of attackers and swears to aid her and make her the next demon king, in order to create a co-existence between humans and demons. On their quest to claim the power of the bird Caladrius, the two bond and eventually become lovers.
Keyaru regards Norn as the most cruel and malevolent person in Jioral Kingdom, and the only one capable of killing him due to her tactical skill. After Norn starts a conflict in Burranikka which ends up killing a friend he got to know, Keyaru ties her up in a basement and has a rabid and sexually excited Freia assault Norn until she loses consciousness, before erasing her memories. He then brainwashes Norn into thinking she was his younger sister, though he gets carried away and makes her infatuated with him.
She is one of the Heroes, and one of Keyaru's main targets of revenge. She is homosexual, and has an obsessive love for Flare; in the previous timeline, when Flare drugged Keyaru and used him as a sex toy, she beat him out of jealousy. In the new world, Keyaru sucessfully took revenge on Blade by first disgusing as a woman (Keara) to lure her, fully knowing that Blade homosexual tendency didn't changed at all. Then Keyaru drugged Blade and put her in situation where she have to pleasure three men at once or risk getting eaten due to the drug Keyaru created. In the end, Blade is eaten by the same three men and died.
He is one of the Heroes and and one of Keyaru's main targets of revenge. He is homosexual and has an obsession with Keyaru. In the previous timeline, he often raped him and called it a proof of his "love". So Keyaru greatly despise him, but at the same time he recognize him as a formidable foe, much more difficult to deal than the other heroes, and in some way as his "teacher" since he learned many of his tactical mindset during the time traveling together on the first timeline. When he met Bullet again in the new timeline, he unconsciously trembles as part of his trauma with him, but soon overcome it as his desire to make his enemy taste hell was stronger. Bullet is also the reason why Keyaru never considers adding another male for his party.
- Kaifuku Justushi Web Novel Volume 4, Chapter 14: The Healing Magician Connects With Eve