Kencho Saikou

Kencho Saikou is one of the characters in Yandere Simulator who's also Megami Saikou's brother.

Description
Saikou Corporation was founded by a man named Saisho Saikou, who had two children: a daughter and a son. He wished to see his firstborn child inherit his company, and so he gave his daughter special training so that she would be able to handle the responsibilities of running a company. At some point, his daughter decided that she valued something else above her inheritance, and she left Japan to pursue a dream.

This was absolutely devastating for Saisho, who had spent a significant amount of his life and fortune training his daughter to inherit his empire. He was forced to rely on his son to inherit the company, even though he had not given his son the same sort of training as his daughter. He advised his son to have multiple children so that if the firstborn doesn't want to inherit Saikou Corp, the other child would take up the responsibility. And so, Saisho's son had two children: a daughter named "Megami" and a son named "Kencho."

Kencho is fully aware that he was conceived with the sole purpose of being a "backup" in case his sister ever dies or abandons her obligations towards her family. This fact was never hidden from him. As a result, his self-identity is based entirely on his relationship to Megami, and his sense of self-worth is derived by comparing himself to her. He is not content to exist as a "backup", and strives to surpass his sister. However, his sister can outperform him in absolutely every way, which has caused him to develop an extreme inferiority complex.

Kencho's father is aware that his son's rivalry towards his daughter is a potential problem, and so Kencho has been forbidden from attempting to interfere with Megami's life in any way. Kencho desires his father's approval more than anything else, and so he has never meddled in Megami's life, not even once - but every day, he hopes that a terrible misfortune will befall her so that his life can have a purpose.

Kencho and Megami do not interact often, but when they do, Kencho is very discouraging and condescending toward his sister in an attempt to mask how she makes him feel. He is aware that his father wanted his firstborn to be a son rather than a daughter; this is his only "advantage" over Megami, and he gloats about it at every chance he gets. His childish behavior rarely has an effect on Megami, but on rare occasions, his words can cut her deep.

Most Saikou family members strive to be as honorable, respectable, and dignified as possible, but Kencho is unlike the rest of his clan. Because he desperately wants to escape his feelings of inferiority and pursue the sensation of superiority, he takes every opportunity to flaunt his wealth and social status over anyone that he considers to be "beneath" him.

Trivia
From what we know, he is smug and conceited.