If I'm going to program this as a visual novel, that requires a bit of groundwork. I need to know how the structure of the narrative will play out, I need to know whee thingss will happen, who could be met, what could be found along the way, and the kinds of events that will shape the lives of our protagonist(s).
The more preparation at the beginning, the more logical the structure of the world. This all links back to the worldbuilding series I did last year.
From the single page of work here, I've got 17 locations identified for events to occur in. I need a bunch of NPCs to interact with (possibly divided into factions), and each with their agendas in the world (that may or may not interact with the stories being told).
But for now I'm trying to think of how the story starts...the dominant idea in my head is...
A few years ago, a drug took hold on the streets, in the boardrooms, at all levels of society. It was highly addictive, highly hallucinogenic, and in many cases lethal. Most of the junkies died, those in high social circles who survived went to rehab, hiding the truth of their addiction. Only a few of those from lower social circles survived, most barely alive. After years in prison, and months in halfway houses, you have finally be allowed back on the street. But you have a permanent bad record, and can never get a job if you admit to being a former junkie...the other option is to lie, but that still means you'll need to hide out on the streets, never gaining a "real" job ever again. You live on cash, because no one will trust you with a credit card. You think the world is out to get you, and not only this world. The drug showed you something else, another world even more dangerous than our own, a world trying to collide with ours...but no one will believe you. You'll need to survive in our world, to act as a defender against the encroaching otherworld.
Needs more work, and I haven't had much chance to look at it today. But it's progressing.