Candle wax
"Itachi-san? Can you do me a favour, un?"
The Uchiha looked up from reading his book to see the bright blonde of Deidara's hair and a big white grin. This couldn't bode well for him.
"Like what?" Itachi said, eyes narrowed slightly.
And from behind his back, Deidara thrust out a … candle?
"Can you melt this with your fire jutsu, un? Please?" He gave Itachi the most pathetic puppy eyes anyone could imagine.
Even though Itachi was the world's strongest known ninja, and possibly the coldest, even he was a little bit affected by that. "…fine."
Deidara squealed in happiness, and set the candle down on the table, then sat down himself, ready to watch.
Itachi put his book aside and formed the seals, then breathed out a small plume of flames. It was enough for wax to start rolling down the candle, and Deidara's one visible eye had never been wider.
Soon, the candle was a puddle of wax. Itachi, his job done, leant back in his chair, but not before Deidara exploded with joy.
"AMAZING! Such fine art, un!" And before the wax had dried to a rock again, Deidara shaped it into a bird. After that, he raced off to find his danna, so he could show him his new piece.
Itachi sat in his chair, wondering what on earth had possessed Leader-sama to let in a boy like that, but shook it aside, and went back to his book.