Sega AM Research & Development No. 1 is a development department within Japanese video game developer Sega that also previously existed as Wow Entertainment and Sega Wow Inc. AM1 spent most of its early existence under the leadership of Rikiya Nakagawa and developed a number of arcade games for Sega. In 2000, Sega split its development studios into nine semi-autonomous companies, with AM1 becoming Wow Entertainment. Wow developed games for the Dreamcast and later other consoles as well as arcade games. In 2003, as part of studio consolidations within Sega, Wow was merged with Overworks Ltd. (originally titled Sega CS Research & Development No. 2 and later AM7) and renamed to Sega Wow. Nakagawa resigned a few weeks later after Sammy Corporation acquired a significant amount of shares in Sega. Sega Wow was re-integrated back into the company the next year. Since then, the AM1 division has continued within Sega.