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I saw that one the other day. It said just some guy. That just means while he has all these expectations but is nothing special himself.

In this context it means absolutely nothing.

As in, there are zero expectations of "the guy".

That phrase is simply comparing the requirements for the two sides:

The girl:

• must be skinny
• must have an hourglass anime
• must like anime
• must know how to cook
• must take care of the home
• must want kids
• must be good in bed

The guy:

• must be a guy

What they are saying is that if you want a girl with that many requirements, you need to consider that you should also be able to match an extensive list of requirements similar to that (whichever they may be). It's not any specific requirement, but by saying "just a guy" they probably mean the guy doesn't pass any requirement they can think a girl may add to their own list.

There's no specific thing you need to work on, but you should work on something. You may put work on your body to become attractive, you may be smart and funny, a very reliable or very charismatic person (not just for attraction but for dealing with people in general). You may be a good person to talk with by being genuinely interested in what others have to say. There's a million possibilities.

As an exercise, imagine spending a day with someone. Try to think of everything you would do together. After thinking of the whole day, now imagine that same day all again, with everything happening exactly the same, but with you in the position of the other person. Would you have enjoyed being the other person in that imaginary day?

Everyone has a thing. A guy with no thing is just a guy.

I’m a man but for me a guy is someone who is unremarkable at everything. Not especially good looking, not especially in good shape, not accomplished in a field or financially successful. Just a guy.

If you're looking to get into the dating scene, I'd recommend these

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