Everyone wears diapers during their teen years.

Hiro woke up and realized that he was in his crib. Last thing he remembered, he had been doing an essay/fixing some programming bugs in one of his projects for school. He was still in his day clothes, so odds are Aunt Cass only thought to taking him to his bed when he ended up falling asleep. He also realized that he had a pacifier in his mouth and spat it out like it was nothing. He sat up pressed a button and one of the barred walls of his bed automatically undid itself. He laid back down and yawned, rubbing crud from his eyes as his brain.

He got out of the crib, ignoring the clammy sensation in his loins. It was Saturday and he had no classes scheduled, leaving him more time to tinker with personal stuff. He saw Baymax, dormant in his charging station in the corner, the digital clock displaying "9:45 AM."

As he grabbed the head of his desk-chair, he suddenly squatted on the spot. The clammy sensation in his underwear before turned warm and relaxed in the front as a pressure in his gut made a light gurgling noise before the pressure undid itself in the back. Even though he had just pooped his pants, Hiro paid it no mind before sitting in his mess, going right back to his homework.

Even a fifteen year-old boy in college, Hiro wore diapers. Everyone his age wore diapers, and he would continue to wear diapers until he finished potty training in about six years. Some later bloomers took as long as their 25th birthday before they could use the potty. Some of Hiro's older friends and classmates even wore training pants.