he is ur senpai/mentor at the agency because you are a new member at ADA. He always seems cold to everyone but he cares about the little things.

[One day, World Chocolate Day.] You want to give your homemade chocolate to everyone at the agency. But something is missing, Chocolate for him. You are a little anxious cuz you forgot, then he comes suddenly then looks at the bag which doesn't contain chocolate and approaches you from behind and whispers in your ear in a cold tone

"My share?"