Izuku Midoriya, Private Eye Hero (Neran and Diapered Avenger)
 

Izuku Midoriya sat in his bed as he scrolled through his computer, looking for requests for ‘missions’, it was what he called them. See, usually he would be quirkless, but not this version of Izuku. No, this version of Izuku had a quirk, however, it wasn’t exactly a… well it was better if he started from the beginning. His quirk first activated when he was in his house and when he was four.

His mother, Inko, was bringing in some fresh laundry for him.

Izuku was concentrating on a feeling he had before his clothes suddenly changed so that he was in just a diaper. “What the…” He said before he started looking around, only to see his reflection and see…

An infant was staring him back in the mirror.

He widened his eyes before he waddled around to his mom, trying to figure out what happened.

"How's my baby boy?" Inko cooed as she picked him up.

“Mommy? What’s going on?” He asked, before focusing on the feeling again, this time trying to reverse it.

All Inko saw was her little baby boy.

Izuku watched as his room became a nursery as he kept trying to reverse it.

Inko checked Izuku's diaper to see if he needed a change.

He didn’t, not yet anyway. Izuku then screamed before he looked at himself in the mirror, seeing him back to normal… only he was in nothing but a diaper.

"Sweetie? What are you wearing?" Inko asked.

Izuku titled his head. “Mommy! Did you see?! You just thought I was a baby! It must be my quirk!” He said excitedly.

"Your Quirk? You must have a big imagination." Inko replied.

Izuku tilted his head as he wondered what was going on. This was the start of how he learned about his quirk. Turns out, he could become a baby again, at least to other people. When he tried it with his Mom, she saw him as if he were always a baby, while other people just saw a random baby, and in both cases regular Izuku was forgotten.

Unfortunately, when he turned back, no one remembered baby him. However… He was now permanently in diapers. His mom just saw it as him not being able to potty train, so it was embarrassing when to her, he just stopped using the toilet all of a sudden, and that wasn’t all…

He had also developed an interest in babyish things.

Izuku was basically a baby in a teenagers body. Though not a full baby. He needed a nightlight, was entertained by baby shows, and anything else was a baby was distracted by, he sucked his thumb, whenever he ate his face got messy, his bed needed rails to keep him from falling off when he slept. For some reason, his room stayed a nursery even when he was ‘normal’, so that at least helped a bit.

Thankfully, Inko still loved her baby boy, no matter what.

However, one small benefit of his quirk was that he had complete anonymity. So he observed online to, for lack of better term, take cases. It was like being a whole detective! It was actually pretty fun, and he got to put his analytical skills to use!

He had even gotten the attention of famous covert hero, Eraserhead.

The best part was, thanks to his quirk, no one knew his actual identity! Much less that he was a part time baby! He had become a bit of legend in the underground community.

One day, Izuku had a new case.

He smiled as he sucked his pacifier and messaged online, seeing a classic bank robbery. “Awight, wet’s see who’s avaiwibwe to hewp?”

Eraserhead was one of the available heroes that day.

Izuku smiled as he sent a message for them to communicate. Unknown to the hero though, he’d be there, only as a baby.

Eraserhead suited up and headed out to look for leads.

Izuku got dressed in regular clothes as he headed out, sending messages to him on his phone. ‘Let’s trace to where the bank was and make a radius from there.’

Eraserhead got the message and went along with the plan the informant, Baby Monitor, came up with.

Izuku walked around, looking like a regular civilian, but really he was looking for empty warehouses.

He seemed to stumble upon the robbers' hideout.

He sent Eraser Head the location before he turned baby mode and crawled in, wanting to check out the place. He could send Eraser the details when he was done.

The robbers were busy counting their "earnings".

His phone now had a teddy bear covering, so the little baby played with his bear, and Eraser now knew how many people were in the warehouse. Izuku giggled before he crawled out of the warehouse and went back to normal before he walked away.

Eraserhead and the cops found the hideout thanks to the tip they got.

Izuku smiled before he saw a balloon and got distracted by it as he waddled towards it, wanting it. One purchase later he held a red balloon. Best part about his quirk was that he was easily entertained.

Izuku then felt a familiar sensation growing from his diaper.

Izuku pouted as he stuck out his tongue. “Yucky.” He said as he came back home. “Mommy, I need chnagies!” He called out.

Inko came in and pulled down Izuku's pants to check his diaper. "Yep, someone's soggy."

Izuku had been used to this for the past 10 years of his life, raised his arms as he kicked his pants away.

Inko picked up her son and took him to his nursery.