O1: Sleep

Kakuzu was a prisoner for the second time in his life, and that realization pissed him off. He had no refuge from the madman who'd joined the Akatsuki solely to haunt him. His neck could tear in two and his right arm could be shoved through his midsection, his eyes could be gouged out and his face smashed against a tree again and again, but he'd [i]still[/i] find a way to make his whining voice worm into Kakuzu's ears. That bitching had become so inseparable from Kakuzu that he heard it even in his dreams.

Kakuzu was in Hidan's dreams too, but that came from a different sentiment.

O2: Pain

There were different levels of pain, though a lesser man than Hidan wouldn't recognize them. Emotional pain was the least poignant of them all, and Hidan rarely experienced it. He suffered the next category, physical agony, frequently enough that it often dulled his emotions. There was the pain of a flesh wound, the pain of striking an organ, and the pain of being torn apart. The last was troubling even to him. Immobility was a bitch. A feeling of uselessness hung over him like a blanket whenever he couldn't move properly, taunting him with the idea of tearing his purpose in life to shreds.

It was different when Hidan felt Kakuzu's black, wriggling threads wrap around him or graze his skin before plunging into the flesh and muscle. He didn't mind that.

O3: Sweat

Physical activity became less bearable when the sun bore its heat rays down on Hidan's pale back. His brow would glisten with moisture, and even he might try and avoid a battle. On those hot summer days when he'd travel long hours through the forests and deserts with Kakuzu, Hidan would throw his cloak off and wrap it around his waist. Kakuzu commented gruffly on how ridiculous it looked, but he wouldn't press the matter.

Hidan noted only mentally how it must have been so much hotter for his partner underneath the layers of clothing he wore (to, as he unduly believed, cater to a self-consciousness that was more befitting of a teenage girl than a hardened criminal). It was half out of curiosity that he reached over and forcibly tore his entire mask off. Long, dark locks fell to Kakuzu's waist. Sure enough, his tan skin was dripping with sweat. Before Hidan could do anything else, a hand was clasped over his mouth and his body was flung backwards into the nearest tree. "Temperamental bastard." He coughed in amusement.