Anime Characters With Shocking Age

Anime characters' ages are sometimes revealed in a way that becomes a meme, showcasing how illogical the writers can be when setting their real ages, habits, and physical appearances.
Information:
1) Non-human characters often have longer lifespans than humans, such as aliens (Saiyans and Piccolo), dragons (Milim Nava), homunculi (Fullmetal Alchemist: Brotherhood antagonists), demons (Demon Slayer), vampires (Kaname Kuran and Alucard), and gods (Hestia and Rory Mercury). This is based on their mythology.
2) In Non Non Biyori's Beach Episode, Hotaru Ichijo is even asked by her teacher, "Are you literally in 5th grade?" due to her physical appearance compared to other people in their town.
3) The vice president in Daily Lives of High School Boys (Nichibros) still has an unknown name.
4) Ash Ketchum is consistently identified as a 10-year-old, from the start of the anime to the conclusion of the 25th season.