It was a dare from, of all people, Mukuro.
"You're such a goody-goody," Gokudera sneered in his charming way as he and Yamamoto walked to school, with Tsuna in the middle of them. He had his lips fastened to the end of a cigarette and was absently puffing away.
"Huh? Me?" Tsuna asked.
Gokudera reddened. "No, of course not!" he cried, bowing his head once, twice, ten times. "I would never insult you, Tenth! I was talking about ihim/i." He stabbed his thumb finger rather viciously in Yamamoto's direction.
Yamamoto wasn't really paying any attention. He had been whistling to himself, watching the birds fly and the wind blow and the trees grow. Now, at the mention of his name, he glanced at his companions. "Hmm~?"
For some reason he couldn't really fathom, Gokudera seemed to get really offended by his response. Gokudera clenched his fists angrily, the veins bulging out like cords on his neck and forehead as he growled, "Yes, you, Yamamoto. I swear, you can be so ditzy, aside from your usual baseball nut way."
"Thanks." Yamamoto was used to Gokudera's no-nonsense personality. He smiled and then nudged Tsuna with an elbow. "Hey, you're a goody, too, right?"
"Ah, I don't know…" The smaller boy shrugged. "I guess. I've been called it before."
"Yeah! It's not a bad thing! Gokudera, you can be one, too!"
"I don't iwant/i to be a goody-two-shoes! And the Tenth is inot/i one!" Gokudera seethed.
Gokudera was really irked now. He had his arms folded across his chest and he was glaring at the pavement in front of him like it had personally slapped him upside the head. "Yamamoto, I don't even know what to do with you…you're too damn naïve."
Tsuna had to agree. "Yep. I'm sure that Yamamoto has never once done something foul, huh? Not like you, Gokudera-kun," he teased light-heartedly and Gokudera grinned; he wouldn't have reacted the same if anyone other than Tsuna had said the same thing.
Yamamoto didn't answer; he just continued to whistle off-key to himself. It really was such a lovely day, with the wind just a slight breeze, enough to ruffle his hair; the sun was shining and the birds were singing and the flowers smelled so nice—
"Kufufufufu. Never have you done something foul, Yamamoto Takeshi? I can change that."
The words were a dry whisper behind the trio. They all stopped walking and whirled around as one to find Mukuro standing there, smiling ominously.
Tsuna paled. "What're y-you doing here, Mukuro-san?" he stammered. Gokudera just glared. Yamamoto recovered from his initial shock and sort of waved.
"I was wandering nearby," Mukuro said, "and I couldn't help but overhear your conversation. I must say, that is truly interesting to know that you, Yamamoto, have not once done anything foul in your entire life. What are you, an infant?"
"Uh, no, I'm older than that," Yamamoto started to answer but Mukuro held up a hand.
"So here I am. I have appeared to propose a solution to this innocence of yours."
"Well, what is it? Spit it out already," Gokudera demanded.
"Gokudera-kun!" Tsuna said.
Mukuro widened his lips into a smile that showed the tip of his teeth, like he was some vampire. "To rid yourself of this innocence, you must spy on (Y/n) tonight."
(Y/n)…the name was familiar. Where had Yamamoto heard it? Then he remembered. (Y/n) was that pretty girl who sat two seats in front of him in math. Since math made absolutely no sense to him, Yamamoto just spent most of the class staring at her from his seat, mesmerized by the swell of her cheekbones and the curls of his lashes and the plump outline of her lips. She was so pretty…
Wait, did Mukuro just say he had to spy on her? "What?"
"Kufufufu. I know you heard me."
Tsuna was slowly inching away. "I don't want to hear anymore of this," he was murmuring.
But Gokudera was smiling. And it was iscary./i "Go on," he instructed Mukuro.
The Mist Guardian flicked his eyes to the silver-haired bomber. "Getting into this, aren't you?" Then he turned back to Yamamoto, who faltered at the sight of the sparkle in Mukuro's eye. "Yes, to become a true man, you must spy on (Y/n) tonight. Once the sun sets. You do know who (Y/n) is, right?"
"Yeah, but I don't see what this has got to do with her…"
"I don't see what any of this has to do with anything!" Tsuna cried. "We need to get to school, you guys, we're gonna be late—and why are you even here, Mukuro-san?"
"She always takes a bath when the sun sets," Mukuro said, completely ignoring Tsuna. "But she always leaves her window open. And her bathroom door ajar."
Oh, this was not headed in the right direction, Yamamoto just knew…
"Her room just so happens to be on the first floor of her house and there is a conveniently-placed bush outside by the window. Yamamoto Takeshi, if you were to hide in the bushes under the cover of darkness and watch (Y/n) bathe…well, you see what I'm getting at, right? Kufufufu."
It was a terrible idea! Yamamoto knew he should protest. But then he thought about what (Y/n) would look like naked… Delicious ideas planted themselves in his head and he felt his face grow hot.
Gokudera was nodding to himself. "That's a good idea, Mukuro," he admitted, somewhat grudgingly. "Surprised I didn't think of it myself. (Y/n) would never even suspect Baseball Nut creeping in the bushes, watching her as she bathes."
"Yes, yes, you understand now? It's the only way Yamamoto Takeshi can lose his innocence." Mukuro cackled. "I like the way you think, Gokudera Hayato. It is very much like me."
Tsuna grabbed the edge of Yamamoto's sleeve. "Don't listen to them, let's just go…"
"No." Yamamoto surprised even himself. He looked at Mukuro. "All right, I'll do it."
"What!" yelped Tsuna.
Mukuro merely grinned. "Oh? What made you change your mind so rapidly?"
It was undoubtedly the promise of seeing (Y/n)'s body. But Yamamoto couldn't say that. Instead, he just laughed. "Hahaha, it can't be that dirty, can it? I'll just get a glimpse and then I'll be gone before she even notices."
Mukuro nodded. "Tonight, then, Yamamoto Takeshi. When the sun sets. Do not forget!" And with his familiar laugh, he was gone again.