"Kishimoto said he didnt want Jiraiya to come back, because he couldnt possibly write it in a good way. Jiraiyas death was a big part of Narutos development and brought him closer to understanding ...

That said, Kishimoto has previously revealed the reasoning behind not bringing him back. Jiraiya's Death In Naruto Was A Shocking One Jiraiya Infiltrated Amegakure The Six Paths Of Pain Combined ...