Protagonist's Appearence Transforms
Manga
Manga where the protagonist or another major character undergoes a drastic appearance change.
Sometimes these changes aren't permanent, but they are notable.
Extended List:
Ouran High School Host Club, Pandora Hearts, Blame!, Black Butler, Gintama, Jibaku Shounen Hanako-Kun, Tokyo Revengers, The Disastrous Life of Saiki K., Gleipnir, FLCL, Yuu Yuu Hakushou, Kekkai Sensen, Vagabond, Merupuri, 20th Century Boys, Saishuu Heiki Kanojo
Sometimes these changes aren't permanent, but they are notable.
Extended List:
Ouran High School Host Club, Pandora Hearts, Blame!, Black Butler, Gintama, Jibaku Shounen Hanako-Kun, Tokyo Revengers, The Disastrous Life of Saiki K., Gleipnir, FLCL, Yuu Yuu Hakushou, Kekkai Sensen, Vagabond, Merupuri, 20th Century Boys, Saishuu Heiki Kanojo