Everyone may have a relationship that is difficult to let go, but there is no place to talk to. Then come to Hokusai. You can choose to talk to everyone, or you can choose to find one person to talk to.
Each story also has an object of sustenance. You can choose to give it to Hokusai, or you can choose to keep it, which also means you choose to let go or continue to remember it.
The protagonist of each story is different, and different people produce different stories in different forms.
There are continuations of everyone's stories, including tragedies and true relief, all told from the perspective of Lord Hokusai.
It's not pure BG, there's also BL.