Disclaimer: Naruto belongs to Masashi Kishimoto.
Orochimaru's ficlet is based
during the arc of the Legendary 3's fight, and the story referred to is
"The Tale of the Gallant Jiraiya." I would swear I read somewhere
that Orochimaru attacked Jiraiya because he was also in love with Tsunade, but
I haven't been able to find a version again stating that, so I might have
Orochimaru had always been subtler than Jiraiya.
During the time that Jiraiya had known him, Orochimaru had never tanned. He once came back from a mission in Wind country with skin that was so painfully red even Jiraiya didn't comment on it, but after it had shed, he was still pale. When Tsunade first started her studies as a medicnin, she made a joke that she would never need a model for the veins and arteries systems as long as Orochimaru was around.
"Huh?" Jiraiya had said, looking over. He hadn't been paying attention to Tsunade's words, just her voice. He had to leave on an assassination mission before dawn the next morning, and was more interested in eating fresh food that didn't have dirt or grit mixed in it.
"Here, show him your arm," Tsunade ordered.
Orochimaru looked at her with his usual expression, one of slightly bored examination, but shrugged an arm out of his kimono sleeve.
Tsunade casually tossed her chopsticks into the box and pulled his arm closer to Jiraiya. "Look! You can see almost all his veins, from his heart all the way down. And the arteries." She pointed to the crook of his elbow.
She started to tug down the bandages he had been wrapping his forearms with lately to show the extended network of the arteries. Orochimaru said dryly, "Do you mind? Tsunade-hime."
She rolled her eyes and let his arm drop. Jiraiya started to reach for it, to show Tsunade that yes, he was listening to her, and hey! was even interested; but Orochimaru pulled away and slid his arm back into his sleeve. Jiraiya ignored the wordless rejection and went back to his food.
He didn't care. Really, at that minute, he didn't care. With all the physical fights he'd been in recently, he didn't want to add a mental one, and he didn't care if Orochimaru was giving these little signs of which of his teammates he preferred more often now. It wasn't like Tsunade was going to condescend to date either of them, anyway, now that she had breasts.
Orochimaru had always been subtler than Jiraiya.
But Jiraiya still thought it was incredibly crass of Orochimaru to snicker at the news of Dan's death.
It was a little known secret that Jiraiya was actually a good writer.
For over five years, he had written Tsunade poems. Some of the oldest ones were bad--terribly bad, enough so to leave her with a permanent distaste for rhymes--and some of them were good; and some of them she read once and then folded up and put carefully away because she was afraid of what might happen if she read them again. And some of them were so perverse that if Tsunade ever walked up to Jiraiya and punched him in the back of the head, he didn't ask for an explanation. He just gave her that cocky grin and invited her to join him in whatever he was doing.
Even while she was dating, she found the poems hidden in her things, like her medical pack, the inside of her sandals, or the lining of one of her bras (she'd given him a broken rib for that one, even though the poem had been beautiful. neither of them answered when Sarutobi asked what on earth he'd done). Tsunade went through boyfriends quickly--either she lost interest or they didn't live up to her standards or Jiraiya accidentally almost ran over them while traveling on one of his frogs. One of them became friends with Orochimaru, eventually disappeared, and pieces were later found in the man's lab. So Jiraiya didn't feel the need to stand on propriety.
When she had been dating Dan for a month, the night before she left for a mission, Tsunade found a poem inside her weapons pouch, attached to the flap so that it wouldn't hamper her when she reached for a kunai or shuriken.
She didn't let herself read it. She went on the mission, lived, came back home, and the next time she saw Jiraiya, she handed it back to him without speaking. He tucked it into the back of his belt with a nod. He didn't write her any more.
She didn't throw all of the poems away when she left the village. Tsunade had learned to be superstitious, and she had a feeling that destroying all of them would be like letting go of Jiraiya's life. She kept the first one he'd given her, with its spelling mistake and horrible rhyme scheme, and her favorites, and the ones that she still wouldn't allow herself to reread. She kept them in an old and battered cosmetic kit while she traveled, one that even a thief or a ninja would overlook unless they suspected her of carrying information, along with an earring that Orochimaru had dropped without noticing during a team mission.
Over twenty years passed before she made herself bury the earring in a small, deep hole beside Sarutobi's grave. She eventually moved the poems to a new battered kit, and reread them all.
If Orochimaru had a weakness beyond being mortal, he supposed it was Tsunade. That's the only explanation he could find for why he is so detrimentally honest with her at times.
He has no affection for her, and no deep attachment either--though she had been more tolerable to work with than Jiraiya until she broke--so they aren't repeating a fable. Orochimaru has read the story, written on an old and frail scroll, and there have been times where if he had thought Jiraiya would accept him, he would have offered, just to spite it. He suspects that Sarutobi had an odder sense of humor than any of them knew. Or that he was a very hopeful man.
Orochimaru tells Tsunade the worst truths casually and without remorse: "Jiraiya is three days behind on reporting in," "Your brother died horribly," "Yes, I laughed," "I was careless when I was killing the Third." He speaks frankly and to her face and waits to see when she will punch him.
She has never once hit him first. The surrounding topography has always suffered before she lashes out at him. Sarutobi had learned that if Jiraiya ever showed up with taped-over bruises and started spinning a tale about a card game with the frogs that went horribly wrong, Tsunade had gotten in a fight with him; and if one of the increasingly emptied homes in the village at that time had collapsed without notice, it had been a fight with Orochimaru.
One of the outer walls of Tanzaku castle suffers the same fate, and it makes him smile faintly, which only angers her more. Beneath the face that hides her, Tsunade's emotions are still as turbulent as they always were.
And still as easily manipulated, at least by him. He watches her falter sharply when he says he can bring Dan and Nawaki back, and thinks This thing has yet to crumble.
He knows the answer when she stops looking at his eyes, and allows Kabuto to do the rest of the meaningless speaking. Perhaps Tsunade isn't a weakness, he decides. A 'weakness' implies that it can control him, not vice versa.
But later, he feels the closest to shock as he has in a long time when she throws herself in front of his sword. He only realizes that his habit of being honest with her has become unconscious when he admits: "Tsunade . . . I wasn't trying to kill you. . . ."
It was the realization that made him finally want to.