Assumptions based on information actually provided, rather than baseless speculation. He literarily asked "How did it get like this" in the first chapter, so it's safe to assume there was more of a discussion off screen
That only applies if the parts not being addressed actually matters. Just because YOU are curious about a detail does not make it important to the story. Unaddressed details can also be explored as a story goes on, once those details become relevant. Not everything needs to be spoon feed to the readers in the first chapter. Be patient and let the story build up it's world
Assuming there isn't a problem until one is actually presented is "toxic positivity?" Do you not understand the concept of "benefit of the doubt?"
Tell me, why would I assume a worse case scenario? Unless you know something I don't, I doubt there will be a violent confrontation or NTR. Maybe if something really pisses off the writer, like with Gal Cleaning, but I doubt it'll happen. "They were sad then, but they're happy not" has been how this story has operated so far, with zero indication that something from the past will reemerge to ruin things. That can change, but until it actually does, I'm going to enjoy the cute fluff that is the focus of the manga
Just checked out Clannad and the premise seems to be a boy with a troubled homelife trying to make a depressed classmate happy. Seems pretty tragic from the get go, so I'm not sure what you're on about. We've got implied child abuse in the first chapter and explicit child abuse in the third. For fucks sake, in chapter six, the main girl finds a threatening letter in her locker. The tones are nowhere near the same. You aren't being realistic, you're ignoring what's in front of you and projecting what you want to see