Kashima Kobato is one of the Class 2C students pulled into another world as a Hero by the goddess Vysis. She knew Mimori Touka and cared about him, though she was too scared and powerless to actually help when things got bad—something that haunted her after his death. Eventually, Asagi forced her to join her group.
At first, Kobato comes across as a nervous wreck. She's timid, easily frightened, and quick to panic or cry when situations get intense. Her main concern is what everyone else thinks of her, which doesn't exactly help in a life-or-death situation. But Touka's death hit her hard enough to snap something into place. Once she realizes just how dangerous Asagi really is, she finds the backbone to push through her fear and actually accomplish something.
She's still wary of Asagi, obviously, but she's sharper than she initially appears. Kobato can read people pretty well—she's one of the few who understands that Asagi doesn't see her as a threat, which means Asagi's more likely to slip up around her. That kind of cautious, clear-eyed thinking becomes one of her strengths.
Back in Japan before the summoning, she was genuinely kind, polite, and empathetic. Those qualities didn't disappear; they're just buried under survival instinct now.
Content compiled by AnimeList.moe from publicly available sources.