 Since his first cameo in the series , director Tetsuya Nomura has stated that Roxas is an important character to the series , and that in order to explain his back story in more detail than done in Kingdom Hearts II , Kingdom Hearts 358 / 2 Days was created . Since his introduction in Kingdom Hearts II , Roxas has received positive critical response from video game publications with most of them focusing on his development in 358 / 2 Days . Various types of merchandising have been released based on his character . 
