Not a spoiler besides the themes
Eh, I guess Jisatsu is generally about youth and finding yourself, what you want to do and the confidence/agency to do it. The adolescent feelings of wanting attention and to be special, the little dreams everyone has and how it clashed with the realities of others, difference of opinions and getting along. All of these many things - GSS but good?
Would need someone smarter to dig harder at the world and death