Tall Order - Chapter 4

“Kacchaaaaan,” Izuku whined, lower lip wobbly as he reached for the action figure, held aloft in Katsuki's hand. “Pleeeaaaase?”

“What's wrong, you can't get it?” he teased, waving it around over his head. “Stupid little Deku can't reach?”

“Kacchan you know I can't!”

Katsuki conceded, planting the toy in Izuku's outstretched hands, amused by the way his pout immediately turned into the brightest of smiles. He never got mad, never stayed upset, always just tagged along with Katsuki like he'd never done anything wrong in his life. Even when he ran off without him after school and hid, leaving Izuku to search for him to go home together; even when he climbed to the very top of the playground and declared it his kingdom, where only those cool enough to climb could sit by his side; even when he got angry and ended up shoving or pushing. It didn't matter what he did, didn't matter how many of their other friends cried or ran away, Izuku was always right there, green eyes sparkling as he watched Katsuki's every move with awe.

“I'll get it,” he said firmly, when Izuku reached for his backpack to put his toy away. “Look how easy it is when you're big!”

“Kacchan is amazing!” Izuku agreed, nodding emphatically as Katsuki handed over the bag. “Thank you!”

Together they nestled the figure safely between his books, wrapped in his spare sweater, and when it was safely away they ran to join a circle of their peers. All week they'd been talking about families – about their Moms and Dads, brothers and sisters, even their grandparents. Katsuki had been waiting for today's topic, though.

“Who thinks they'd like to get married one day and have a big family of their very own?”

Most of the hands shot into the air, including Katsuki's and Izuku's both, and Katsuki grinned when the teacher smiled at them.

“What kind of person would you like to marry, Katsuki?”

“I'm gonna marry someone super tall and strong like All Might!”

“But Kacchan!” 

Izuku protested immediately, pouting again. Katsuki could already hear it in his head – the whines that he wanted to marry All Might, and Katsuki's carefully crafted explanation that All Might is too old and he just wants someone like All Might, that neither of them could actually marry All Might – that would be weird, you big dummy!

“I wanted to marry you!”

The teachers cooed and giggled, but Katsuki hardly even noticed, still staring at Deku with his big eyes, so painfully sincere.

“Then you'll just have to get big and tall, dummy!” he answered finally, folding his arms.

“Kay!” Izuku nodded, eyes wide and shining again. “I'm gonna be as tall as All Might when I grow up! Kacchan will marry me then, right?”

“Only if you can get taller than me!”

“I will! I promise! I'll get super big and Kacchan will be impressed!”

“Fine!”

He held out his pinky finger, and Izuku accepted it happily, beaming as they shook on it. From that day forward it was set in stone – after all, everyone knew pinky promises were the most unbreakable oath in the world.