This tag is to be used if the appearance of the protagonist ONLY is different from their actual age. This tag can be used to describe the protagonist of a cultivation novel who doesn't age despite being very old, though it is not recommended as it can become a very generic tag. Best to use this tag only if the fact that the appearance is different from actual age is actually used in the story.

Please note that the age mentioned is physical age, and NOT mental age. That might come under the Mature Protagonist tag.
[You have entered the dungeon at Gwachun Station’s 1st Exit.] When former high school student Kang Woojin finds himself returned back to Earth after being forcibly summoned to a foreign planet for 20 years, he soon finds that Earth is not the same, normal place as he once remembered it to be. With his former strength and age reset back to zero, watch Kang Woojin as he gets back on the path to becoming the Earth’s strongest Necromancer!