Another story request. I wasn't given besides a Ryohei/Tsuna story so we'll see how this goes.

Full summary:

Tsuna was shot with a new bullet that Reborn found. Growing cat ears and a tail were not what they were expecting at all. As he learns to deal with his new instincts and features, he has one more problem to deal with. It's spring, and guess what that means for animals? Mating season! Once Reborn finds out, he tries to fin the one who's Tsuna's mate. Finding out it's Ryohei, he locks them in a room together. I Wonder what happens...

I know pretty long...but that's pretty much the layout so far. On to the story!

He had found the bullet on a mission. He went solo, as he was hired to kill a man. No reason for Vongola to be involved.

Upon his return to the Sawada residence he had laid in his hammock in his students room, studying the bullet with intense care and focus. He wondered what the thing did...it's color was brown, and was slightly longer than usual. Just before it's tip lay two small triangles. It was obviously not a normal bullet, so what did it do?

He had to know.

So he decided to test it on his precious student tomorrow morning. Not like it would make any drastic change in his current lifestyle at all.

As Tsuna woke the next morning, he knew immediately something was off. First of all, he wasn't beaten awake by a mallet, Nana wasn't calling for him, and no kids were running around crying. He slowly made his way out of bed and got dressed into simple jeans and a blue and white t-shirt. He made his way downstairs to the living room, and stopped.

Reborn was sitting there casually, sipping an espresso.

"R-Reborn?" He called hesitantly, not wanting get a new bruise so early in the day.

"No training today Dame-Tsuna. Were doing something different." The tutor replied, lowering his favorite drink on to the coffee table.

"A-and what w-would t-that be?" Tsuna asked nervously. He really didn't want to go on some crazy quest to save the world again. Leon crawled down the baby's arm, transforming into a gun once he reached his masters hand. Reborn didn't give any time to run as e aimed and fired.

The shot hit its mark on the boys forehead, said boy falling backwards from the force of the impact. Nothing happened for a while, as the boy lay there, and Reborn began to worry. Had he actually killed his student?

But then Tsuna began panting, hard, and shifting around as if in pain. It became apparent as to why when the boy turned on to his side: There was something growing out of the base of his spine, and as Reborn looked closer, his ears were shifting and morphing as well.

He watched in horror as the transformation finally seemed to end. The boy moaned, seeming to still be in pain , and lay still. He had passed out. Reborn took this time to look him over fully, his horror turning into great amusement.

The boy had a new set of cat ears perched atop his head, which twitched occasionally in his sleep, and a long slender brown cat tail which had curled around his waist. As he looked closer, he saw Tsuna's nails had turned into claws, and had fangs that peaked out his top lip. Reborn pried the boy's mouth open a bit to get a good look, when he noticed his tong. He ran a finger across it, shivering at the roughness, before looking for more changes. He lifted one of the boys eyelids to discover oval shaped pupils, and that his eyes had turned into the amber of his Hyper-Dying-Will form. His legs looked misshapen, and he realized they were for if the boy wanted to walk on four legs.

So that's what the bullet does. Now his student was a Neko. Woops...

Hope it was good, I've wanted to do a story like this for a while now. Reviews please!