Souei/Relationships

Rimuru Tempest
He is his lord and master. Souei believes that Rimuru installing him as a ninja has unlocked his full potential, and he is forever grateful.

Benimaru
Benimaru and Souei are rivals and best friends. For Souei, Benimaru who is the son of the lord was not his lord. Instead, they both ended up serving Rimuru as his executives.

Shion
Souei and Shion seem to get along and are friends. Though he does tend to "run away" from her cooking. He thinks of her as brutish and incompetent, even mimicking Rimuru's voice to call her 'half-wit secretary', to which she seems flattered. When Milim thought they were siblings because of their horn correlation (having only one where Benimaru and Shuna have two) he's said to have made a 'fearsome' face.

Shuna
Souei and Shuna seem to get along and are friends. Shuna has called him a 'bad boy' in a good-natured tease.

Hakurou
Souei and Hakurou seem to get along and are friends. As his trainer, Hakurou taught him how to fight.

Souka
Souka has the utmost respect for Souei and may be even in love with him. She is very attentive to his instructions and looks for any opportunity to impress him, and maybe try to win his favor. Soei is aware of this of course, and tends to stalk and tease her the most, feigning ignorance to poke fun at her at every opportunity. He may also like her in return.

Ranga
They began to show more interactions when Rimuru went in his journey to Ingrassia, both Ranga and a Soei clone hiding in his shadow. While the wolf tried to get to know the other better Soei would make teasing comments like him liking cats better than dogs or saying how 'it must be good to be so popular' when he was forced to take a bath by the kids. The clone is always shown smiling when Ranga whines at his words, showing how much he likes to poke fun at others and how the simple-minded wolf makes it so easy.

Glenda
After she made a failed assassination attempt against a Kingdom of Ingrassia Prince meant to frame Demon Lord Rimuru Tempest on the orders of the Rosso family, she was confronted and defeated by Souei. In the end, she was spared the death penalty due to her being an Otherworlder having been unable to disobey her orders due to being under a summoned curse, so after Rimuru removed the curse from her, she was permitted to join Tempest and became Souei's subordinate.

Litus
She's one of Hinata Sakaguchi's direct subordinates and followed her captain when she went to talk things out with Rimuru following the events of Walpurgis. Soei followed Rimuru's orders of stalling the templars so they won't interfere with his fight with Hinata, as his opponent Litus was completely outmatched and developed a large crush towards him after his 'torture' during said stalling.