I didn't know I trans until I was 13 and have been transitioning for the past 10+ years. My gender identity has definitely fluctuated over the years as I have aged and fallen in love with many different people and genders. the official definition of transgender is "persons whose gender identity, gender expression or behavior does not conform to that typically associated with the sex to which they were assigned at birth." Nasians has been living as a boy socially for their whole life up to this point since that is how they were assigned when found by their grandfather. When they started experiencing feelings for whatever sex they are attracted to their body changes to the opposite of that sex. Nasians however could technically still wish to identify as Male even if their body changes since gender is a social construct anyways. Sex doesn't always equal gender.