Access: One minute walk from Seibu Kyujo-mae station (Seibu Ikebukuro line).  

There are a variety of ways from Central Tokyo to this ballpark.  Here is the easiest way, guaranteed:

Make your way to JR Ikebukero Station.  From JR Ikebukero Station take a short walk inside building to Seibu Ikebukuro Station.  Depart Seibu Ikebukero Station on the Seibu Ikebukero Line toward Nishi-Tokorozawa.  Get off at Nishi-Tokorozawa (not be be confused with Tokorozawa).  At Nishi-Tokorozawa transfer to the Seibu Sayama Line and its train to Seibu Kyujo-mae, the stadium station.