Complex sentence: The original staff members were Tabata, Yusuke Naora and Tetsuya Nomura, and development was slow due to most of the team being devoted to "The 3rd Birthday".
Split into simpler sentences: The original staff members were Tabata, Yusuke Naora and Tetsuya Nomura. Development was slow due to most of the team being devoted to "The 3rd Birthday".