Corse Party D2: Depths of Despair
The prologue shows Ayumi and Satoshi trying to revive their dead friends after the events of the original CORPSE-PARTY. The ritual attempts to claim Ayumi's life, but Satoshi runs into the circle and gets sacrificed instead.
At first he appears as the shadow following Ayumi. He then appears along with Yuka and Yoshiki and start torturing Ayumi, but they are all interupted by Sachiko appearing and using the magic of the book to make them dissapear. Ayumi later finds him in the hallway of the basement and apologises to him and they all go back to the gravesite where they bury the book. They all say their goodbyes as Ayumi leaves the school. After that Satoshi's soul can finally rest in peace.
Corse Party D2: Fatal Operation
Most of the Satoshi's appearances come with him being mentioned by Naomi.
Satoshi appears in two of Naomi's flashblacks, along with her in Heavenly Host after Yuka's death.
Satoshi is mentioned by both Naomi and Ayumi as the latter reveal the true reason behind Satoshi's death.