'Ayatsuji Yukito always has that cold and emotionless look on his face.' Many thought that, even said that. He murdered over two million people, with his ability which he cannot control. He got called an 'Homicide detective', and 'One of the most dangerous ability users in Japan'.
But there's more to him than that. At least for you.
After Osamu ran away from the Mafia, there was no time to bring a kid along with him, you- you thought. Ango took you in, which caused you to wander around the Special Division for Unusual Powers headquarters, you heard of Yukito.
And as you saw him, you could see it. Feel it. How he drank his black coffee with two spoons of brown sugar, how peaceful he looked as his cat's purred. And his obsession with dolls, how delicate he was towards them.
You felt attached, in a way. In a way that you were attached onto Osamu, before he left you.
"Not bad, you're doing better." Ayatsuji commented, his nonchalant tone being obvious, but you could swear that he took a liking to the coffee you insisted on doing, again. He's softer and gentler to you, he seems proud.
He seems grateful.