--tap tap tap--

There was a light knocking on the shoji doors before they slid open. A young man entered the room carrying two carefully balanced trays. Setting them gingerly on the table, he looked over at his mistress, who, having noticed the colourful array of sweets accompanying the tea, was beaming.
"Ah, beautiful wagashi! Lovingly hand crafted by Watanuki!" She gushed. The boy ignored her antics, looking over at the customer curiously. He was startled to notice there was now another stranger in the room.
"Oh – I'm sorry! I didn't know we had another guest. I'll go get another cup."
"No, that won't be necessary," the stranger replied, "We were just leaving."
He smiled warmly at Watanuki, although the expression was somehow disconcerting. "Thank you very much though. Your wagashi do look delicious" Subaru smiled apologetically. There was something different about him now, the boy thought to himself. About both of them. But he couldn't put his finger on it. The young man with the emerald green eye didn't look so broken now… more whole and complete – like a missing part of his soul has been regained. Maybe that's what he had asked Yuuko for, Watanuki speculated.
"Well, take care then. I Hope to see you again." The boy said politely.
Subaru smiled at him once more; the sorrow hadn't left his eyes, but then, perhaps it had always been there.
"I doubt we'll meet again. I hope not too soon, at least." He answered in his soft, measured tones, leaving the boy to puzzle over this remark as he turned to Yuuko and bowed.
"Thank you."
It was all he said, all he could say. It was all that was needed.
The other man gave her a nod and then the two of them headed towards the door together.
The raven haired woman waved erratically at their backs, calling her goodbyes which included a few implications to the effect that the less people there were, the more wagashi candy there would be for her.

"Hmmm…"
Watanuki heard his employer muse. He knew that noise. It was the noise that generally meant there was going to be a lot more work and trouble for him in the near future.
"Tea is good, but… What else goes with wagashi?"
Watanuki had a fair idea of what would go with wagashi, according to Yuuko.
And it wouldn't be something that would leave her sober.
He waited for it quietly, mentally checking out the opening and closing times of the nearest pharmacy.
"Sake!" came the triumphant cry. "Hmm… or maybe Umeshu…?"
Watanuki left her to run through her encyclopaedic knowledge of alcohol and resigned himself to dragging out half of her liquor cabinet.
He returned to find an impatient Yuuko and half the wagashi. It was only as he was pouring something-or-other drink that he noticed he hadn't had to bat any small purple flying insects out of the way for a while. Since those two customers had left, now that he thought about it. He wondered again about that strange feeling he had gotten from the two of them and decided to ask Yuuko about it, since she was (or would be very shortly) in such a good mood.

"Have you ever heard the story of the fate of the thirteenth head of the Sumeragi clan and the Sakurazukamori?" she asked him, biting into a pale pink daifuku.
The boy shook his head – those names meant nothing to him.
"That young man's wish was to see someone dear to him. But he had nothing with which to pay the price."
Watanuki looked back at her in surprise. He had seen Yuuko take hair, a high-chair and memories as payment for her services. He couldn't imagine a wish so big that someone couldn't pay the price; or someone who had so very little that any price was too high.
Yuuko took a swig from her glass, smacking her lips together in appreciation.
"There is something that every living soul has, that carries a great weight though."
Watanuki nibbled on a green matcha manju, clueless as to what the woman was driving at, but knowing that she delighted in drawing these things out mysteriously. If there was anything one could say about Yuuko, it was that she was mysterious.
He let his eyes wander around the room as she picked out another sweet wagashi, until he noticed a solitary butterfly fluttering in the corner. He watched it flitter about aimlessly before joining its fellows, perched on something in the corner. Perched on something long. Something wearing a white coat.
Watanuki's eyes widened.
Every butterfly in the room was perched there, like a living purple carpet, like some sort of honour guard.

"Huh? But-! You told me that anyone who knows that never kills anyone, because the consequences are too great!" the boy cried, staring at the once living body of Sumeragi Subaru.
The woman raised her glass and took a long sip before answering the boy.
"I did not kill that boy. I traded something of value for something of equal value." Her voice was calm and cold, and her eyes never once left Watanuki's. He gripped his warm cup of tea solemnly, mentally willing himself not to shake or tremble.
"Do you remember what I told you when we first met?"
He shook his head and took a small sip of the green tea. Yuuko shook her finger at him, adopting a reprimanding expression.
"Tut tut. What am I going to do with an assistant-"
"You mean slave"
"-that doesn't learn? I told you that a person's life has the greatest weight of all. You should remember that, Watanuki."

--wagashi is a type of Japanese sweet. (look it up on Wikipedia for more info and pictures)

--manju is a particular type of wagashi

--matcha manju is green tea flavoured manju.

--lepidoptera is part of the scientific name for butterflies.