Killua rolled the toy car along the grass until it careened into another (complete with his sound effects). It was a game he played every time he went outside, and it was something he was able to do without letting Alluka, who was busy with her Sailor Moon dolls, out of his sight.

Killua was used to keeping an eye on Alluka, but this time was a little different.

He dropped his cars and turned around, meeting the eyes of his new responsibility.

There, lying on his back on a spread blanket, was Kalluto, Killua's new brother.

Kalluto didn't cry a lot, but he didn't smile a lot either. He just quietly lay there, looking up with curious, magenta-colored eyes.

But today, Kalluto's eyes weren't just curious. Killua could tell just by looking at him that he wanted something. Killua smirked slightly. And I bet I can guess what it is.

Killua reached both of his arms out towards Kalluto, and, just as Killua thought he would, Kalluto reached back.

"Alright, Kallu, I know what you want." Killua said, picking the baby up and holding him just as his mother had taught him to when Alluka was a baby. "There, you happy now?"

Kalluto didn't respond, but he did relax a bit, the longing look disappearing from his eyes.

Alluka curiously looked up from her game. She laid her dolls inside the dollhouse and headed over to Killua, looking over his shoulder. "Kallu's so small."

"Yup."

"Was I that small?"

"Uh-huh."

"Nii-chan?"

"Yeah?"

"Can I hold him?"

Killua looked back at her, a bit surprised by the request. Then, he smiled. "Sure, but be careful."

Alluka nodded eagerly. "I will!"

Killua carefully handed Kalluto to her and taught her how to hold him properly, though it was a bit difficult since Alluka was only a toddler herself.

Finally, when Kalluto was safely in Alluka's arms, Killua allowed himself to relax, laying on his stomach in the grass next to Alluka. "When he's a little older, maybe Kalluto will play with us."

Alluka grinned. "I can't wait!"

"Will you be a good big sister?"

Alluka nodded. "I promise!"

Killua looked thoughtfully down at his brother. Alluka was still too young to understand what being a big brother or sister meant in this family. It meant you would spend every day drilling assassin's rules into your younger sibling's head, and you would have to help with the endurance training.

No, being a big brother or sister wasn't all fun and games in this family, that was for sure.

Good luck, Little Brother, Killua thought, it'll be a tough road ahead.

"Nii-chan, look! Kallu's got my finger!"

Broken from his troubling thoughts, Killua allowed himself to smile at the innocence of his younger siblings. Well, at least that'll be a long time from now. I'll just enjoy it while it lasts.

(A.N.: Oops, Killua sounds too mature for his age! ): Oh well, I guess Zoldyck children do mature early, so...)