I don't think he'll change completely, but it's obvious he changed a fair bit in this episode. I'm not even basing that conclusion on my interpretation of his actions. I'm basing it on how the characters in the story, such as Haru, Yume, and Shihoru, reacted to Ranta's behavior. They were literally wide-eyed with Ranta this episode. Haru even explicitly said that Ranta wasn't acting like himself.

It's up to you to make assumptions about Ranta's behavior and rationalize it any way you want, but I'll side with simplicity and agree with the characters in the story.