U-San's charity 3D concert:
There were talking segments about the nature of the abuse in between songs, but it was a bit rambly and all over the place, so its hard to put it all together.
When U-San parents were arguing the Mother apparently threw something rather heavy that landed on U-San which is why their leg is injured to where even just playing basketball, U-San broke that leg twice. U-San talked about how their brother tried to help with the day to day abuse and how that part of U-San's life is reflected in the Lore. When the brother called for help, he wouldn't call the police but instead called the Mother's (i.e. one of the abuser's) friend, because he was afraid to dishonour the family by involving the police. The Mother's friend (who I think is female) also apparently was the one to take U-San's virginity (there was some talk about the acts U-San was forced to do, but I'll spare those details). U-San had thoughts of killing their own father and when talking to a friend about it the friend suggested running away with their help, after which I think the police get involved at some point but U-San was seemingly not ready to talk about that yet.
Michi called in for emotional support at one point and VShojo apparently helped with the organization of the concert.
Nijisanji's Hex tweeting about the concert on his PL:
New cover by U-San: