One who admires; one who esteems or loves greatly.

An admirer is someone that is attracted to transgender people sexually. Typically these are of the same genetic sex, for example, a male and a transvestite. Many admirers feel that they are “straight”.

a person who admires; someone who esteems or respects or approves

Transphile

a person who backs a politician or a team etc.; "all their supporters came out for the game"; "they are friends of the library"

a friend, so don't refuse my care and concern for you on purpose, or stop dispensing them to me out of consideration

See Devotee below. Some consider "admirer" to have a more positive connotation than "devotee," but your own mileage may vary.

An individual who enjoys the company of TGs.