Kaval, Eren, and Gido are the adventurers who Rimuru briefly encountered. We learn their guildmaster is quite the taskmaster, sending them back out to Jura to further investigate the disappearance of Veldora after just three days of rest. They are accompanied by a raven-haired young woman in white cape and mask named Shizu.
Meanwhile, Rimuru surveys the fruit of his overpoweredness, as the Dwarves he brought to the village immediately begin to make a big impact on the goblins’ development. He also names 500 more goblins to evolve them so they won’t be wiped out in the power vacuum caused by Veldora’s vanishing.
The adventurers soon get in over their head, and end up getting chased by a pack of giant ants. Shizu uses her mastery of fire and not inconsiderable combat skills to destroy the ants and save her comrades, but ends up missing one, and almost fainting just before she can kill it.
That ant is destroyed by Rimuru’s Black Lightning, and he introduces himself to them all, including Shizu, whose mask came off in the hubbub, revealing a face Rimuru saw in the crystal ball; the person he’s “destined to be with.”
Rimuru takes them back to the village where the goblins put them up in a hut and feed them meat, and they have their introductions. Shizu is putting out all kinds of Japanese vibes, and turns out there’s a reason for that: she was summoned to this fantasy world from the same real world as he was, only in her case, it was during an bombing raid in WWII, just after her mother was killed by debris.
While the details are scant, Shizu was apparently summoned (by at least 30 mages, according to Veldora) to serve as a weapon. At first the big cheese in charge of bringing her there doesn’t think anything of her, but then has none other than Ifrit use Shizu as a vessel.
Shizu seems glad to have met a fellow Japanese, and even happier when he shows her his memories of how well the country has fared since she left. But there are times when she collapses; perhaps a symptom of the “curse” she bears. And then there’s the whole reason she’s there: to serve as a weapon formidable enough to defeat, say, a dragon…or even, perhaps, a slime that ate a dragon? Whatever her motives, I’m glad we’ve finally been introduced.