The developer is Korean. And back then, there were decency and porn laws (i.e., adultery and other forms of cheating were arrestable crimes). Heck, pornography in general was illegal there unlike most other developed countries like Japan. People were arrested for just
viewing them online (which posed quite the conundrum for a tech-savvy society such as South Korea) let alone operating websites or facilitating in the creation of any type of porn (such as this game). The last time I did a good check about it several years ago, the South Korean government were just starting to ease up on some of them such as the aforementioned adultery charges.
According to Wikipedia after typing the above, that mostly seems to be the case.
Quoted below from this link:
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It is what it is, and it's assumed that the Korean government somehow got wind of the dev after the game went up on dlsite, his various forum activity became known, and his blog site went live. Someone probably ratted him out.