A boy who acts recognizably feminine but can still be easily identified as male. "Onee" type boys will often be of this demographic, owing to girlish speech patterns or hobbies.
Most characters of this type will have an interest in topics typically associated with femininity (dandy-style fashion, beauty, cute things, etc.) and often are depicted in coquettish poses. They may wear high heels, jewelry, makeup and/or nail polish. Common hairstyles may be wavy or flipped.
Not to be confused with otoko no ko (sometimes referred to as "femboys" in English), which is a boy whose physical appearance is feminine regardless of his personality. Also not to be confused with the term and archetype of "okama", though characters of either type can have girly boy traits. Crossdressing does not automatically make a character a "girly boy" either.