Unbelievable game and a stellar debut.
There's a lot of ways visual novels can take advantage of of the medium to make something more than the sums of their parts. I appreciate that this one reached far back to the minimal stylings of the "sound novel," leaving the music and visuals to set a base level of atmosphere–in this case a damp, dark, oppressive one–and letting the writing take the lead, trusting in the reader to flesh out a sensory model of the vivid world inside.
The prose carries itself with the dim, slimy confidence of hard-boiled detective fiction and the story gave me the kind of thrills I've only gotten from the best episodes of the X-Files: those moments where the veil is at its thinnest and the only thing scarier than supernatural violence is the insidious banality of the state which can hardly contain it, let alone wield it.
The cultural elements brought much to the story that I'm still thinking back to. I've been considering differences in policing in the US vs Japan, forced confessions and hostage justice, the new left and student movements of the 60s, Di's mom's Americanisms in Japan compared to her Japaneseness in America... and how all of that fed into the paranoia at the story's core (and there too was personal joy in seeing such rare complexity in a mixed/haafu character).
Among the very best I've read. Can't wait to see what this group does next.