Kosako Shunichi (小佐古俊 Kosako Shunichi?) is an anime-original character introduced in the Toaru Kagaku no Railgun S anime series. A bespectacled student of an unspecified institution in Academy City, he is a member of STUDY and acts as Aritomi Haruki's second-in-command. It is a group that desires to show their power in their esper-obsessed city and plays an antagonistc role in the Silent Party Arc.