"That was wonderful, Shiro-san! How did you do it?!"
Shiro laughed at the girl’s excitement. “Who knows, perhaps I am just gifted by the lord.” He crossed his arms, putting one of his hands on his chin. And with a large, ridiculous grin he continued, “Oh, or maybe I am a descendent of an ancient hero from ages long past?” He laughed happily, obviously joking around, but not mocking her. He was simply enjoying their conversation to the fullest.
He leaned forward and put a hand on her shoulder before whispering, “But you should be careful, there is always something watching you in this city. You should always keep what you can a secret. Please understand why I cannot tell you anything.”
Shiro liked this girl, he really did. She was very earnest and very upbeat from what he has seen, like a child. There needs to be more people like that. But there is no worth in there others now knowing exactly what he is capable of, even as simple in his world as the storing of black keys. Simply due to the multidimensional nature of the nexus many have most likely never encountered a weapon like it.
And even if they do it is always good to keep some things hidden away for a rainy day. You learn that quickly in the Burial Agency.
Standing upright he looked at the statue with began to crack, before crumbling to dust. “There goes my new lawn ornament. Oh well, at least the kids won’t realize another attempt was made. That should make them feel a little bit safer."