"i wish i was normal" isn't really mary sue-ish, imo
You would think that but let me just give you a little quote here:
"I am good at too many things, it is a freeken curse!"
Having a character wish to be normal, while highlighting how perfect they are... is typical Mary Sue fanfare.
This isn't Psycho 100 where the point was that the power the main character has... wasn't as important as everyone was pushing. That he couldn't obtain what he actually wanted through his powers, even while everyone insisted that was true (Which is to actually change and gain talents outside his powers). Which, of course, makes perfect sense in the series and is well framed... rather than being empty words and sentiments.
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I'll put it this way... a VERY Mary Sue thing to do... is to make your character's flaws... advantages.
Mahouka for example has a main character whose weakness is that he has weak magical power.
In a typical GOOD anime such a character would find ways around said weakness through preparation and intelligent use of his limited powers.
What the anime ACTUALLY did was make his weak magic power completely irrelevant... because he can essentially cast hundreds of spells a second AND give a huge middle finger to the laws of magic AND physics through BS-ways.
All the while still INSISTING that his weakness was in fact a weakness worthy of feeling sympathy for. In spite not only it not affecting him, but his advantages make him far more competent and potent then anyone else (Basically the anime wants you to believe he is a Blind Swordsman... But in reality he is a Swordsman with bionic eyes)
(This anime/manga is the ULTIMATE unintentional parody to the point where you would SWEAR it is a parody... It MUST be a parody)