[A quiet sigh escapes him because... wow, Naruhodou hasn't figured it out yet? He thought he was quite clear about it when explaining the Professor case. Well, time to spell it out, then. The pipe is placed in its stand by the ashtray for a moment. He walks across the room to pick up his violin and begins to play a tune similar to this. As he does so, memories of his most valuable friendship begin to flood his mind. The lights dim a bit, a comfortable warmth spreading through the room.]

My partner... came to England sixteen years ago to study forensic pathology. He was a doctor back then, and I was but a mere student working in a hospital lab. However, that's not why we were introduced. He was in need of a housemate, you see, in order to halve his rent. We hit it off right away, despite our differences. I had never met someone so polite, so discreet and so very honest. We became the best of friends. We discussed science, we enjoyed music, we solved the oddest of mysteries... And we danced- oh, Mr. Naruhodou, you should've seen us in our prime. Nowhere in our world could I find anyone who understands my way of thinking the way he does.

[Sherlock pauses, his bright smile weakening somewhat. The lights flicker. Even so, he doesn't stop playing the violin.]

He was with me for six whole years and then... Then he was forced to leave England behind once more. Iris couldn't go with him. He's a professor now, teaching at a university in Japan.