He isn't with anyone. If he was with Shizuku this whole manga wouldn't be a thing.Author just keeps making more arguments for why he should dump Shizuku and go out with Yako instead.
Also Takt continues to be suspicious as shit man, his childhood girlfriend is gone for a month and he's like "yo buddy, you seem pretty down. Do you miss her, dude? How about this, if your stall wins, I'm gonna tell you to do something and you gotta do it bro, that'll cheer you up for sure"
I continue to be annoyed we know basically nothing about that guy when he's the 3rd part of the mystery here, but I've already fuckin' made that post so I'm not gonna do it again, but god DAMN it. We keep not learning anything about the premise! At this point, we know more about Yako, the other younger girl introduced recently, than we do one of the central pillars of this manga's core conflict! Come ON