For the essay I'm thinking along the lines of looking into Osamu Tezuka - nicknamed the 'Godfather of Anime'.
Some things to look into would be
- The influence of Disney on his work
- Anime and Manga and their origins
- Tezuka's influence on Manga and Anime
- Metropolis and the film based on his work from 2001 also influenced by Fritz Lang's Metropolis
- Astro Boy and the recent CGI remake.
If not just looking into anime as a whole - influences of disney, style, key people (Osamu Tezuka), influences on western animation and its popularity.