Akihabara might get the most attention but Ikebukuro is a major player in the anime-manga-gamer universe. Case in point: Animate's Ikebukuro store is the largest of its kind in Japan. It also gets extra kudos from girl geeks (who are known to prefer Ikebukuro to Akiba), thanks to several floors devoted to their favourite series.
Animate Ikebukuro
Shinjuku & Northwest Tokyo