So the dads had a relationship, and Einshi's (E) mom found out and decided to leave. His dad decides to leave E with the other dad. I think he wrote the book for E before committing suicide? Anyways, Kuruto's (K) family ended up taking him in (despite how people thought it was weird). This probably happened after K's brother accidentally pushed his off the cliff because he treated E like a replacement brother. Then there was a scene where the cat was killed. I thin the cat was either ran over or in an accident, and his brother tried to hide it. Then they got older and K moved out. E moved in with him and tried to go to the same high school. FF three year and E grew taller and made it into the HS. He keeps confessing to K, K is all like: don't say that bc I treated you kindly for impure reasons. Bro shows up, the friend (Aruma?) s rooting for E, and etc.
At least that's what I interpreted from the story. Dunno if that was any help though haha.
I don't even understand what i don't understand it feels like i'm looking at a blank canvas while reading this, i'm just confused on the story and i don't know why is that. The only thing i understand is their fathers have something on their relationship.