Japanese Light Novel Book Club discussion

What is the first trapped-in-a-game novel or light novel?

.hack//AI Buster?

If we're talking "trapped in a game" specifically, the .hack// project is the oldest I can think of. Based on that, I think the oldest of the light novels associated with the project is AI Buster.

It's not the oldest "isekai" series, though. Wouldn't be surprised if Tezuka had one, but the oldest I can think of off the top of my head is Magic Knight Rayearth I from 1993.

AI Buster was originally released in 2002 in Japan, so if anyone knows of an older "trapped in a video game" novel, I'm curious to know too.

Yes, specifically, "trapped in a game".