The Immortal Ninja of Norrisville High

Randy has been the Ninja for 800 years. He lives in the home of the chosen family guardian that has watched him since he was a century old. Howard Weinerman stumbles upon Randy's room when working for a window he broke when playing a video game. Howard convinces him to attend his high school. What kind of adventures will an 800 year old ninja have in the school he protects?