Task: Question Understanding
Input (English): Context : It was later released for the Sega Game Gear in Japan on November 19, 1993 under the name Sonic & Tails (ソニック＆テイルス Sonikku to Teirusu), on November 23, 1993 in North America under simply Sonic Chaos and in Europe in November 1993 under the same name. 
Question : What series is the episode Sonic Chaos part of?
Output (English): series