Saw the novel. You were right. What were they cooking?
Basically, Kiyotaka was trapped in the White Room by his father. To make an escape, he went to ANHS.
Now, the person to give Kiyotaka information about it was a butler named Matsuo. Matsuo helped Kiyotaka, and it is mentioned later on that it was because he had a son himself named Eiichiro and got pity on Kiyotaka. This way, he helped Kiyotaka to escape the White Room. Atsuomi, Kiyotaka's father didn't like it, so he fired Matsuo, and not only that, but he caused heavy problems in his life. Atsuomi is a very influential person, and political giant who has both huge power and respect, just that he also does a lot of illegal stuff, running the White Room is probably one of the biggest sins and he uses government funds and funds from other influential people to run it.
That's Atsuomi for you. But continuing Matsuo's story, it's just that he died by burning himself to death. His son Eiichiro also suffered a lot. He got admission by passing a very difficult entrance examination, but due to Atsuomi's power, he got expelled from there. He didn't give up and continued to apply to many high schools, but the result was the same, he was always rejected despite being hardworking and disciplined. According to Atsuomi, Eiichiro was working part-time at the time, and had no guarantee of his own future, at the age when he should be in a high school and focusing on his own education.
Kiyotaka's single action and taking help of Matsuo caused an entire family to get ruined. When he was informed about it, he didn't care.
Now, fast-forward to Year 2 Volume 3, the story about Eiichiro is further revealed. Nanase develops Eiichiro's personality and begins to talk and behave like him, all due to the fact that she was traumatized, and deeply cared about Eiichiro. From the plot, you can say that Nanase had a thing or two for Eiichiro. Remember I told you how Kiyotaka's father mentioned about Eiichiro's state, and he was alive at that time, working part-time? Well, in Year 2 Volume 3, it has been revealed that Eiichiro also hung himself and gave up on his life. So, a family which could have easily risen up from being a family of a butler to a successful one was ruined just because someone helped Kiyotaka to escape.
And again, Kiyotaka's natural reaction to this was still the same, as heartless as ever. In fact, all of this was revealed to him when he was engaged in combat, and nothing changed.