This paper analyzes the effects of being removed from a stock index on stock returns and firm value. As passive investment funds that track index grow, the mechanical selling associated with index changes has become more noticeable. This study focuses on the revisions of TOPIX, a major Japanese stock index, and examines the impacts on over 400 companies that are removed from it using an event study methodology. Previous research on global indices such as the S&P 500 has observed negative effects on the stocks removed, this study also finds significant negative impacts on the stocks removed from TOPIX. Although significant negative impacts are observed for stocks that are removed, the effects don't last long, unlike with large-cap stocks.