since the masuda's didn't really give us an ending (just the fact that popee isolates himself to Alaska ) I have my own interpretation : after a few years popee is still in Alaska doing different researches for new projects, while he's going even more crazy and determined to do something in order to be appreciated by people, while working he glances at his stuff that he bought with him, he sees the picture of him and kedamono when there were still at the wolf circuz it makes him froze for a second and he starts to think about the past, on how it was before he made a deal with boron, his face softens (instead of having that crazy looking grin he had when he's doing something dangerous) he thinks about his sister Marifa, kedamono, kedamono Jr, and even popo (but not papi since he absolutely hates him) he then asks himself "what am I even doing ?" so he takes the idea to go back to the village (or city) he goes to see kedamono first, kedamono is absolutely shocked but he's really happy to see his friend he immediately goes to hug him (even tho popee doesn't really like hugs, since it's from kedamono he accepts it and hugs back) keda jr also grew more the last time he saw him popee goes to hand shake him (in a very professional way like he's doing business) they all just sit together, popee definitely looks less "crazy" or "insane" he just looks like a tired human who's feeling better now, he finally understands what love feels like and what loving feels like, then he remembers Dr popo and decides to go to him to, he knocks on the door (he knows where he lives) popo opens it, he also looks kinda tired but still looks the same (the same way he looked before popee left) , when he sees popee right in front he's really surprised and his first instinct is to yell at him (in a comedic way) saying things like "where the hell have you been!!?, why didn't you said something and just left without leaving any messages!?" popee looks a bit guilty and says to himself "there he goes yelling again, well at least I'm used to it" then unnecpectedly popo also hugs him saying that he missed the times where they would just throw hands at each other and do childish things, popee gets surprised from these he never expected popo to even care about it, but he did which makes him feel even better, so he just lets popo hug him, a few minutes after the hug popo is still working but he's not at the D&D company anymore (he's just minding his business, selling useful gadgets to make money) after they talk a little popee goes back to kedamono's place and decides to get therapy to get better emotionally (like his insecurities) and also to learn to control his anger in a more healthier way in order to not go insane (the way he was after going to Alaska) now popee is better, of course he still has his flaws but at least he's better at controlling them and now he's having healthy relationships with his friends , he's also doing a new job now, a cook (since his hobbies is cooking I assumed that he would be a cook instead of a scientist) kedamono visits his place to see how he's doing (he also helps popee when he needs helps) , popee is in contact with popo they talk sometimes but not all the time since they both work a lot, and they all live happily ever after