From DDLC Wiki
Pen in hand, I find my strength. The courage endowed upon me by my one and only love. Together, let us dismantle this crumbling world And write a novel of our own fantasies. With a flick of her pen, the lost finds her way. In a world of infinite choices, behold this special day. After all, Not all good times must come to an end.
The poem clearly parallels Monika's actions in "dismantling" the world of the Literature Club to be alone with the player.
The line "In a world of infinite choices, behold this special day" echoes a similar sentiment in the song which Monika sings in the credits.