Self-harm does sometimes get explained as a way to gain a measure of control, though this isn't the philosophy I've heard from anybody who's self-harmed before. Also I'm unsure about the title. Self-harm isn't quite the same as masochism. Maybe it's a translation thing? Or maybe the author just really does not know what he's writing about. Because, to be clear, what's portrayed is definitely self-harm, and not masochism. Masochism is generally about short, temporary bits of pain that go away quickly and has been consented to. It's generally a sexual thing and is associated with BDSM. Self-harm deals with longer-term pain, stuff that doesn't go away without significant amounts of time and/or help.