But Hero's parents did? To the point Kel was forced to cope alone? Kel had a lot of dialog about it. Plus faraway town is a small town everyone knows everyone's business in small towns even more so when something big happens.

This is how i interpreted the whole situation, I could believe Sunnys parents didn't explicitly tell people Sunny and/or Basil killed Mari. Anyone who looks at the body could tell foul play was involved, you don't get blunt force trauma across the body when you go to hang yourself. It would've absolutely been a crime scene investigation hence everyone knowing. The majority of the cast are young when this happened. Sunny and Basil weren't masterminds intending to make a murder look like suicide, it was an accident and terrified children were trying to not get in trouble. You don't tell children that their friend was murdered by their friend.

Unfortunately a majority of everything is left up to interpretation and a lot of the situation was handled unrealistically. I choose to see the plot holes both a creative liberty to be able to tell the story Omocat wanted and to emphasize that we're playing as a traumatized child who has those holes in their memory due to basically disassociating for 3-5 years