The Heart of Homra
Saruhiko joined Homra straight out of middle school because his best friend (Yata) thought they were cool. At the time, Saruhiko never became close with the majority of Homra but he was attached to Tatara Totsuka.
Totsuka is responsible for new members of Homra and as such looked after Fushimi and Yata when they initially joined. Because of this, and Totsuka's friendly personality he made the extra effort to befriend with Saruhiko when the rest of Homra could not be bothered. He noticed that Saruhiko wasn't fitting in at first and made every effort to include him in events. He failed, primarily because Saruhiko distrusts the idea of family and is incapable to dealing with other people in a mature and responsible way. Totsuka makes an effort to test Saruhiko's limits by teasing him, calling him by nicknames he knows Saruhiko will hate in an effort to get Saruhiko to speak up for himself.
"That kid's interest... or maybe I should say his focus, he's just clinging way too hard to one single thing." - Tatara Totsuka
He made every effort to show interest in Saruhiko and although he was little help in dealing with Saruhiko his efforts earned him Saruhiko's respect. After Saruhiko leaves Homra Totsuka continues to show concern for him. He will often ask Kusanagi how he thinks that Saruhiko is feeling. He even goes so far to tell Fushimi about Yata and how he's doing because he knows that Saruhiko wouldn't dare ask about his old friend. Totsuka doesn't think of Saruhiko as a traitor and it allows him to be more open in front of him. He like Mikoto and Kusanagi realize that this was the best for Saruhiko.
When Totsuka dies Saruhiko tries to hide his sorrow and rage simply because it did not fit in with the apathetic mask he showed to the world. Despite that he is unable to hide it completely. It marks one of the only times he displays emotion beyond his casual annoyance. His strong feelings about Totsuka's death end up working against him when pursuing Kuroh Yatogami and Ysahiro Isana. Kuroh is able to sense his rage and detect Fushimi before he attacks. It is only once their names are cleared that Saruhiko is able to mask his emotions once more.