There is info given on the OFFICIAL Disney blog and site stating Hiro Hamada is 14 years old (here and here). It's not disputed, and not uncertain. I don't understand what is leading you to believe he is 12.
Ryan Potter is a real person, and he was born September 12, 1995, making him 18 years old until September 12 of this year, when he will turn 19 years old. You can't just change the age of a real person as you see fit.
Neither of these ages are open for your debate, and no one appreciates having to constantly revert your edits on the Hiro Hamada page. Hiro Hamada is 14. Ryan Potter is 18. Please stop changing them.
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