For those of you who don't get it, from my understanding, it's a metaphor.
He wants to keep the dragonflies he caught together with him forever, but really it's outside factors that lead to there deaths that were pinned as a "suicide." Also if you notice, the dragonflies he caught are mating. Hence why it's a "lover's suicide."
I'm sure this is starting to ring some bells at this point. Rei and Nagi are meant to parallel the two dragonflies, who wanted to die as lovers who were just two strangers-akin to how insects mate randomly. They think they tried to do it of their own free will, but in truth it was Rei's dad that killed them, and Gen was forced to bury them.
Now is the part of the metaphor that I'm conflicted on. Either Gen doesn't want to bury the dragonfly "lovers again" and so he feels like in order to keep what he has, he has to keep trapped together, and within his hands so the things he deems as precious aren't snuffed out by Rei's dad or other external factors, or he thinks that in order to have the things he wants, he has to be like Rei's dad and be the one who decides when things live or die and be in control of the town.
So basically, it's to show Gen's mindset and how he's gotten to this point.
Hopefully my ramblings/my thoughts help you decypher the point. It's not the clearest metaphor and it could have been better thought-out, but this is what we've got and it may be easier to understand as the chapters go on.
@Marokkboy @satirn @musicfreak12 @kanjutbautai
I'm curious what Gen's thoughts on the other childhood friend are. We know she says she's holding him back, so what is the connection between the two in terms?