Solo Leveling Novel Volume 4 was written by Chugong.

It’s time to take back Jeju Island! After multiple failures to recover the island from the S-rank ant-type magic beasts that swarmed the island, the South Korean and Japanese Hunter’s Associations have forged an alliance to reclaim the land from the beasts. But even for such an elite group of hunters, this will prove to be the toughest challenge yet!