Ash Ketchum sometimes does this:
I'm sure this macro is simply ignorant of some Japanese body language he's using. Another example is here:
I can't recall any other anime character who does this, though, so it may be more idiosyncratic than I realise. What, if anything, does it mean when a person does this?
This gesture, typically seen in fiction such as anime, manga, rather old films or dramas, and typically done by young boys, indicates one's pride, confidence, and/or embarrassment.
In Japanese fictional works, you'd see characters, usually young boys, do this gesture when they feel proud or confident when someone has praised them or their achievement. This gesture is also seen when they feel embarrassed or bashful when someone has praised them for their achievement or thanked them for their kind deed, etc.
You won't see real people do this gesture in real life, though, at least in present-day Japan.
I'll introduce "人差し指で鼻の下を触るしぐさの心理学 Psychology of a gesture touching under the nose with the index finger" written here as the answer.
Since the original text is written in Japanese, I'll translate it into English for the sake of convenience.
People who touch or rub under the nose with the index finger are feeling some tension and stress, or even fear to let others know what they really think of.
Because the gesture means that they are trying to relieve the tension or stress that they feel.
Furthermore, by rubbing under the nose, concealing the mouth, they are unconsciously trying to keep their opponent from realizing their intention or feelings.
Even when you fail in something and become awkward, you would try to get a sense of security by touching under the nose.
And, even when you feel pleasant as if you're praised by someone and feel embarrassed, you may touch under the nose to hide your embarrassment.
Therefore, if your opponent begins to touch or rubs under the nose with the index finger, you're better to remember what the previous conversation was, and identify the opponent's psychological state.
If a man starts touching under the nose after being praised, you can judge that he is embarrassed.
Also, if your partner is often touching under the nose at going out on a first date, you can judge that the partner is distracting the tension or embarrassment.
Furthermore, if the person touches or rubs under the nose often during a conversation, you can judge that he/she wants to hide the intention or feelings of himself/herself because he/she has something that is hidden.
In this way, even if it is the same gesture, the meaning will differ depending on the situation, so I would be pleased if you understand the intention or the feelings of the person carefully expressed by the gesture.
By the way, since I remember that a man like Stalin pulled the end of a mustache and behaved arrogantly, isn't Gary Andrews30's comment a similar gesture to that even if he hasn't a mustache?
Based on Dragon Ball it's uses more for excitement and arrogance. I rarely see them us it for embarrassment, but I've definitely seen it.
