Moe is a character trait attached to certain characters (mainly female) that elicits the feeling of a "desire to protect" from the audience. This feeling always brought forth by some circumstance or attribute that belittles the character, such as acting in a helplessly naive fashion (), some crippling illness (Misuzu, AIR), are simply the classic "maiden in distress" (Rukia, Bleach), or are simply younger (So many examples...) and therefore on a relative scale empowers the protagonist (and by extension, the audience) in the context of the plot. Obviously the attribute is argued among characters and there are conflicts of opinions as to who can be categorized as moe and who cannot, but generally the trends for moe are always present in the above forms. Which is why you never see a woman who was completely self-reliant, of mature age, has worldly knowledge, et cetera considered moe. As primal as it may be, women as equals is not an enticing idea for men with low self-esteem (Read /a/ and Japs).