Tsuna first feels hunger when he is four-years-old.

His mother hadn't been home then, and he remembers feeling the hot pinprick of a hundred burning needles clawing through his throat, aching to be soothed, a painful thirst that sought to be quenched, and he could do nothing but heave the water and food he's forcefully trying to swallow to make it all stop. He's crying, he thinks, mind adrift in a space that numbed what he was feeling, but his body felt it all, acted on whatever it was that craved to be scratched at the back of his throat. He didn't understand what the pain meant then - still doesn't understand several years later but he knows better now, doesn't he? - and he is barely breathing by the time his mother comes back home with a bulky black bag which she bodily drags inside the living room with worried yet unsurprised eyes.

He watches her, teary-eyed, watches the quick and efficient rip of plastic, watches the drop of a heavy arm on wooden floors, watches the thin trickle of red and the shock of white peeking through brown.

"You must be hungry," Nana says to him in that kind, affectionate tone of hers, her smile fond as she wraps her hand around the thick wrist. She tugs, the arm tearing from the strength of her pull, and she presses the wrist against his lips. "Go ahead, Tsu-kun," she urges, kindly combing his hair back with her other hand and giving him a gentle nudge. "Eat. You'll feel better, I promise."

He isn't thinking anymore, the movements of his arms and his head and his mouth all driven by an instinct that lurked at the corners of his young mind. His mouth opens reflexively, fanged teeth gleaming with drool, and he bites.

His teeth sink and sink and sink-

Nana looks at him with pride in her eyes.