Anime/M

Ma

 * Macross: Although this franchise is not directly about giantesses, the plot focuses on the war between human and alien giant humanoids (among which, there are giantesses).
 * Magic User's Club - TV-EP12:
 * Magical Angel Sweet Mint - EP45:
 * Magical Shopping Arcade Abenobashi - EP08: Arumi, in a fit of fury, becomes a giant girl, destroying a school.
 * Manga Sekai Mukashi Banashi - Alice's Adventures in Wonderland: Anime adaptation of Alice in Wonderland.
 * Matchless Raijin-Oh - EP43: Reiko Ikeda is enlarged by a monster, then she helped Raijin-Oh (a mecha) to fight a kaiju.

Me

 * Medaka Box: It is about the life of a perfect female teenager (a literal Mary Sue) with super powers. There are a couple of episodes with brief GTS scenes.
 * Merc Storia: The Apathetic Boy and the Girl in a Bottle: It takes places in a world where humans and monsters coexist. The protagonist, Yuu, is a healer apprentice and possesses the ability to tame monsters. In a quest to regain the memories of Merc, a girl confined in a bottle, the pair embarks on a journey. In almost all episodes, there are brief interactions between Merc and another felame character (para-giantess).

Mi

 * Midnight Occult Civil Servants: The series features angels, such as Adiel, who are either large amazonesses or small mini-giantesses, as well as a silkworm-human mother another named Manari.
 * Miniforce: This is similar to Super Sentai and Power Rangers, but it involves little animals who transform into humanoid "rangers".
 * Mirmo Zibang!: The whole animé treats the chibi theme (and these are miniatures), which implies the presence of para-giantesses in almost all its 172 episodes.
 * Mirmo Zibang! - EP005: Kaede is shrunken, but she comes to interact with some women (para-GTS thematic). On the other hand, there is a brief moment in which Kaede becomes giantess (but is little remarkable, because it does it inside a structure that does not allow us to compare sizes).
 * Miss Kobayashi's Dragon Maid S - EP07c: Kanna finds a fairy when investigating for a class assignment.

Mo

 * Monkey Typhoon - EP49: The protagonists must fight against a giantess who acquires her powers through music.
 * Monogatari: One of the longest-running slice of life franchises in the anime world, where the illustrator (mangaka) Hajime Ueda participates and manages to sneak some GTS scenes.
 * Monster Girl Doctor: A human physician has several patients of different species throughout the series. In some episodes there are para-GTS (women interacting with tiny fairies). Episode 8 is special, as it deals with a gigantic woman who has a cold and the protagonist must cure her.
 * Mouse - EP06:

My

 * My Hero Academia: Mount Lady appears for a short time, a giantess superheroine. The latter has been very popular within the GTS community (in her respective article explains why). There is also a hero named Ryukyu that can metamorphosize into a large dragon.
 * My Monster Secret - EP??:
 * My Next Life as a Villainess: All Routes Lead to Doom! - SE2-EP07: There are moments when Sophia is a fairy while being with Catarina (para-giantess)
 * Myriad Colors Phantom World: Typical epic fantasy anime with high school characters. Among the characters, there is a SW who sometimes interacts with normal women (thus giving para-GTS themed).
 * Mysterious Joker: This series is also known as "Joker". In the story, there is nothing in the world that the mysterious phantom thief Joker cannot steal. He goes after one treasure after another in unpredictable capers with seemingly miraculous tricks.