@Umetsu It's not based on nothing. We see in the photo album that his father is notably missing from the photos with his mother and his father is always depicted as leaving him behind or being away, indicating there was split of some kind. It's not a profound leap in judgement to come to this conclusion given his father's very dismissive attitude towards him.
Given we've only seen his mother in photographs, she's constantly mentioned as being absent or gone, and we know that his house has just tragically burned down, it's an inference to assume she has died, and probably in said fire. And even if she didn't die in the fire, it's still heavily implied he lost his mother in some way and it's outright confirmed his dad walked out on him, which is plenty dark, even if it's played for comedy. I don't think this is making up evidence, because it does show us these visual indicators, such as the fact his mother is not wearing her wedding ring on her left hand, which is where most people wear their's due to it being closest to their heart.
Also, please work on your grammar. I don't know if English is your first language, but here's a fixed version, so
you don't confuse others.
Don't imply dark stuff that based on nothing, please. You can confuse overs.
P.S.: Nothing has been said about his mother: literally. And his father just ran away, like comedy element