Title: - If it looks cute and harmless...

Rating: - M

Pairing: - Izaya x Shizuo

Disclaimer: - I don't own Durarara

Warnings: Izaya

Summary: - AU Izaya was born as a half neko, who wants Shizuo as his mate.

"Shizu-chan." Izaya ran up to the blond, jumping on his back. "I'm bored." Shizuo straightened up, continuing to walk. Izaya had a habit of jumping on his back, it was to do with his dna. Izaya was born as half human, half cat. Izaya was more athletic than normal humans, he had a long black tail and cat ears. He wasn't the only one, the population was halved now. The half breeds and the humans.

Strangely enough, Izaya and Shizuo were friends. Maybe because when they were introduced, Izaya had jumped on his back and started purring. At first it had pissed the blond off, but looking over his shoulder at Izaya sleeping on his back without any worries, made him happy. He was a monster, a human cursed with enormous strength, no one got close to him and everyone was afraid of him.

"Watch your nails, Izaya." Izaya's nails were slightly stronger and tougher as well. So far those were the only differences, between the two races. "Sorry, Shizu-chan." Izaya shifted, his head resting on the blond's shoulder. "It's fine. We only have one more lesson until lunch." Izaya groaned, another boring lesson learning, what he already knew. "Hmm. Nap time."

Shizuo blushed as Izaya nuzzled his neck, softly purring as he slept. Making sure Izaya's legs were tightly wrapped around his waist, he continued on his way to class. "Shizuo. Izaya is with you again?" The blond nodded, moving over to his desk. "Izaya wake up." The half neko yawned, rubbing his eyes. "Go to your own desk." He was glad when Izaya climbed off him.

"Shizuo, you two are always together." The blond shrugged. "I'm worried Izaya will do something to you." Shizuo laughed glancing behind him at Izaya desk, where the teen was sleeping. "What's he going to do? Hug me to death? We've known each other over a year and he hasn't done anything. Shinra sighed, he didn't know how sly or cruel, Izaya could be.

The class finally ended, Shizuo stood up, heading to the roof with Shinra. He didn't stop as Izaya once again jumped onto his back, throwing his arms around the blond's neck. "Where are we going?" Shinra looked over at Shizuo's red face and Izaya's content expression. "The roof. What did you bring for lunch?" Although he already knew the answer.

"Ootoro, what else?" Shizuo smiled. Izaya had an unhealthy appetite for tuna, though he couldn't talk. "Shizu-chan has cakes again. I can smell the sugar from here." He had an unhealthy appetite for sweets, he couldn't have anything without sugar. "Shizuo, You need to eat a balanced diet." Izaya folded his ears down as Shinra lectured them about the importance of eating the correct foods.

He finished just as they reached the roof, where the rest of the group were. Kadota, Erika, Walker, Togusa and Vorona. Erika and Vorona were half neko's the same as Izaya. Vorona smiled at them, waving at Shizuo. Izaya glared at her with narrowed eyes, he jumped down from the blond, sitting next to him as he opened his lunch. "Tuna again?" Izaya smiled. "You can't have any, Dotachin."

Kadota shook his head. "I didn't want any. Be careful Erika will steal it." Izaya glared at the otaku. Erika shrugged, ignoring the food completely. "Shizuo, what are you doing after school?" The blond finished his mouthful of strawberry cheesecake. "I have to pick up Kasuka." He had noticed Vorona coming on to him, flirting at every possible moment. It was the one reason, he wouldn't be left alone with her.

Vorona sighed, her face red as she walked away. "What's wrong with her?" Shizuo didn't understand women, let alone neko women. Shinra studied the retreating girl. "She's going into heat." Izaya hissed, moving closer to Shizuo. "What do you mean?" Shinra turned to the group. Izaya already knew what he was going to say, as did Erika. Every neko had been told by their parents it would happen.

"You know how normal cats go into heat, right?" Everyone nodded. "Well the half- neko's are the same. When they reach a certain age, they will go into heat." He sighed when Shizuo looked blank. "Think of it as a human on aphrodisiacs, but they only sleep with whoever they choose as their mate. Vorona needs to find hers." Shizuo nodded, feeling sorry for the blonde.

"Vorona's staying at home until it's passed." Shizuo nodded, walking out of school. "Izaya, I'll see you tomorrow. The neko nodded, reluctantly letting go of the blond. "See you tomorrow, Shizu-chan." Shizuo watched him skip out of view. What Shinra had said stuck in his mind. When would Izaya go into heat? Apart from Erika and Vorona, he didn't know any other neko's. Would he have to stay home in pain as well?

A month later he found out. Izaya's face was flushed, his eyes slightly bigger and watery than usual. "Izaya, Are you okay?" The Neko nodded, for once not jumping on the blond's back. "I'm fine, Shizu-chan." Shinra watched him warily. "You're going into heat." Shizuo blinked, reaching for Izaya's chin. Izaya mewled into the touch, making the blond blush.

He grabbed Shizuo's hand, pulling him along the corridor. Shizuo followed, as Izaya led him into the bathroom. The door closed, the neko pressing up against Shizuo. "Shizu-chan." The lust filled purr, went straight to the blond's groin, which Izaya happily palmed. "I-Izaya. What are you doing?" Heated eyes fixed on his own. "I need you, Shizu-chan. It hurts."

"Izaya stop it. You need to find your mate. That's what Shinra said." Izaya smiled up at him. "I have, it's you Shizu-chan." Shizuo blushed, grabbing Izaya's hand. He had just learnt that Izaya was gay and that the neko had feelings for him. "I'm sorry Izaya." The neko blinked. "But I want you Shizu-chan." His other hand reached for the blond, only for him to be pushed back. "Izaya look at me, I'm not a neko."

Izaya froze, letting the blond push him away. Shizu-chan didn't want him because he wasn't the same? That was the only reason. He didn't move as he heard the door close. "Stupid Shizu-chan. I decided you're my mate, stupid protozoan." The blond hadn't said he didn't love him, it didn't matter. His Shizu-chan would come to love him, if he didn't already.

Shizuo stared blankly at his desk, not listening to the teacher. Izaya's desk was empty, the neko hadn't come to class. The blond felt guilty, he had feelings for Izaya, but the neko had his own people, his own neko mate. "What happened?" He glanced up, meeting Shinra's questioning gaze. "Izaya's in heat." Shinra nodded. "Did you?" Shizuo shook his head. "No, he has to find a neko mate."

"Be careful." That was all Shinra said before he turned away. Shizuo went through the rest of the day worried about Izaya. No one had seen him since the morning. "Do you think he went home?" Shinra shrugged. "I don't know what Izaya does." It was as he was leaving school, that he turned around, feeling someone watching him. There was Izaya, looking out of the classroom window.

"Shizuo, you should leave." The blond shook his head. "I need to fix this, we're friends." Shinra groaned, rubbing a palm over his face. It wasn't his problem, he had warned the blond. "See you tomorrow." Shinra watched the blond walk back into the school. "I doubt it."

"Izaya?" He didn't know what he would say to the neko, he only knew, he felt uncomfortable when Izaya wasn't around him. He opened the door, blinking as he saw Izaya wasn't looking out of the window. The neko was curled up, sleeping on the teacher's desk. Shizuo sighed, closing the door behind him. "Izaya?" The neko was asleep,

The blond ran a hand through Izaya's hair, hearing him purr at the contact. Red eyes blinked, fixing on the blond. Shizuo backed away from his friend, not recognizing the smirk or dangerous glint on his face. He could almost hear Shinra saying I told you so. "Shizu-chan, I knew you'd come back." Izaya jumped from the desk, crashing into the blond.

Shizuo groaned as he slammed into the desks, sending three of them flying as he hit the floor. "Watch it, Izaya." Izaya smiled at him, a carrier bag in his hands. "I was thinking about what you said." Izaya reached into the bag. "I know you're not a neko, but you're still my mate and we can fix it see." Shizuo gasped in horror as Izaya held out two blood covered ears. "What did you do?"

Izaya shrugged, throwing them behind him. "Yeah, they won't do. Maybe Shinra can do something. But until then, these are fine." Shizuo blinked at the small plastic headband with yellow cat ears. Izaya slid it into his hair. The blond sighed. "This doesn't change anything, Izaya." He pushed against the floor, ready to stand up. Izaya smirked, sweeping his legs out from underneath him. No matter how strong the blond was, he was still clumsy.

Shizuo found himself on his stomach, hearing a click and something digging into his wrists. "I'm not finished." Izaya climbed on top of him, rubbing against the blond. "I can smell your fear, Shizu-chan." Fingers pressed into his mouth, against the back of his throat, forcing the blond to swallow and gag. "There we go. Now you're in heat too."

The blond whimpered as Izaya rubbed against his ass, biting his neck. He could feel his body getting hotter. "Don't bite me." Izaya slashed the blond's uniform with his nails. Shizuo shivered as the cold hit his already sensitive skin. Slicked fingers rubbed over his entrance, before sliding in. Shizuo arched his back, while Izaya's other hand reached around his front, fingers curling around the blond's erection.

The fingers stretched him, making room for something bigger. Shizuo moaned in disappointment, when they were removed. "Shizu-chan, I have something else for you." Izaya pulled something else from the bag. The blond closed his eyes. "After all, Shizu-chan needs a tail to be a cat. Shizuo glanced behind him, watching Izaya lube up the vibrator, with a long blond tail attached.

"Don't be scared, Shizu-chan. The tail isn't real, see." Izaya brushed it against the blond's face. Shizuo tensed as he felt the tip press into him. "Relax, Shizu-chan." His member was gripped once more, filling him with pleasure once again. His heated body accepted the vibrator, Izaya pulled it out before pushing it back in as far as it would go.

"Now you look like a neko, look Shizu-chan." Izaya flicked the switch, making the blond whimper. The neko pulled out his phone, snapping a picture. "Iza-ya." Izaya slid the phone back into his pocket. "Yes, Shizu-chan?" The blond bit his lip, his body shaking. "P-please." Izaya raised an eyebrow. "Please what?" Do you see now Shizu-chan? This is what Shinra was trying to warn you about.

"F-fuck...me." Izaya smirked, pulling the vibrator out. "Do you accept being my mate?" Shizuo shook his head. Izaya growled, gripping onto the blond's base. "Shizu-chan. Don't you love me? I can smell you're arousal. Your heartbeat is faster, every time I climb on your back." The blond closed his eyes, trying to focus on something, anything. But Izaya was touching him again, making his body sing.

"Will you be my mate?" Shizuo cried out, he knew he was about to come and then Izaya was holding his base. The blond whined as his orgasm was stopped. "Shizu-chan." He didn't care any more, tears leaked from his eyes, he needed release. "F-fine." Just do it, he needed Izaya inside him. Izaya smiled, the innocent one he was used to seeing, before he undid his pants, lining his hard on up with the blond's entrance.

Shizuo pushed back against him. "Ah." Izaya let him adjust before pulling out slightly and thrusting back in. He changed angles until, Shizuo moaned, knowing he had hit his special spot. Izaya bit his neck, marking his Shizu-chan as he moved in and out of him. This time Izaya let him release. "I-zaya." He could listen to the blond say his name forever and he would. Once nekos chose their mate, it was for life.

Shizuo now knew two things. Izaya wasn't cute and innocent and Shinra was right, which he probably wouldn't live down. He knew he was stuck with the neko, Izaya wouldn't let him go. Not that he minded, but it meant his now ex-friend wouldn't have a family in the future.

Izaya pulled out of the blond, unlocking the handcuffs. Shizuo glared at him tiredly, before his eyes closed. The neko pulled out the cleaning clothes from the bag, washing his mate. Putting everything back into the bag, he snuggled up against the blond, knowing from the beeping in his pocket, Celty was on her way.

End

Extra

"Mommy, mommy." The blond haired neko, opened his tired eyes, looking down at his youngest son. "What is it Psyche?" Shizuo gently picked up the black haired child. "I had a nightmare." The blond sighed, tucking Psyche under the covers with him. "With me and Izaya do you think we'd let anything hurt you?" His son smiled, shaking his head. Shizuo stroked his head. "Mommy, why do you feel so hot?"

"It's nothing. Go to sleep." Shizuo ignored the feeling in his body, closing his eyes. He could feel Psyche do the same, his arms wrapping around his son. Psyche laid next to his mother, watching her with worry. Once he was asleep, the child climbed out of the embrace, climbing off the bed. He grabbed the phone on the bedside table, scrolling through the contacts.

Hello, Shizu-chan. Psyche smiled hearing his father's voice. "Daddy." There was a pause on the other end. Psyche? What are you doing with Shizu-chan's phone? You should be in bed. Psyche glanced up at the bed, where his mother was shivering. "I had a nightmare. Something is wrong with mommy." Instantly the call ended. Psyche smiled knowing his daddy was on his way back.

Izaya opened the bedroom door to their room. "Daddy." Psyche ran across the floor, clinging to Izaya's leg. "Izaya rubbed his hair, brushing over his son's cat ears. "Psyche, can you go back to your room and stay with Delic?" Psyche nodded. "You'll make mommy better?" Izaya smiled down at him. "He'll be fine." The child smiled. "Good night Daddy."

Izaya climbed onto the bed, hovering over the blond. "Shizu-chan." The blond's skin was hot. Watery eyes opened looking up at him. "Izaya?" The black haired neko groaned at the tone. "Woah." Izaya found himself underneath the blond. "Shizu-chan?" The blond's lips attacked his. "Izaya. I need you inside me now." Izaya blinked. "You're in heat."

Izaya reached for his phone, sending a message to Shinra and Celty and one to Namie. Izaya flipped them back over, so he was on top. "Celty will be here to pick up the kids and I've cancelled work. I have you all to myself." Shizuo smiled up at him with lust filled eyes, he was glad Shinra had made some improvements to his body. "If you get me pregnant again, I'll kill you." Izaya smirked. "If you say so, Shizu-chan."

End