Originally Posted by
A Black Falcon
I'd be shocked. The thinking was, once the game has shipped, why keep the source? You're done, and moving on to your next project, so just toss the old stuff. This is a Japanese version of the kind of mentality that led most TV broadcasting companies in the 1950s and '60s to overwrite their old tapes, destroying all copes of many classic TV show episodes, for example, but worse because there the thing is entirely gone, while with games at least the finished games exist on cartridges, boards, or discs, and most games released on consoles or arcades are backed up thanks to pirates.
On that note, why would a suicide-battery game need source code more than other games, considering that all of those games can be played in an emulator?