I think I'm gonna hate it when Aiko shows up again. It seems he's forgotten about her, on that last page(that's who I'm assuming it's referring to). I feel like this tiny bit of development we just witnessed will crash down the minute he sees Aiko. Like, don't get me wrong, I want to see what she's been up to, but I don't want to see Punpun get fully depressed again, it seems like he's starting to lighten up since Sachi showed up.
Anyway, Sachi is already looking to be one of my favorite characters, so I hope she's gonna be apart of the story for a while.