Everything is from Arc 4's narration and monologue. I don't think they are serious spoiler but...(skipped)
Otto was born in a merchant family. Because he was born with Blessing of Word, his language learning was much slower than normal.
(Blessing of Word enables him to communicate with any organism, including mabeasts or even plants)
Even when he could understand human language by controlling and shutting down his blessing in age 8, his behaviors unfitting to his age and pure bad luck caused many failures.
His Blessing was known to village kids, but it just made him more weirdo and even it was forgotten among them.
He finally ran away from his hometown when he had some problem with the nobility (He used information from his blessing to harm someone's honor) From then, he acted as independent merchant.
(Although many people(including Subaru) consider him as a coach driver)
His most recent activity was selling iron and buying oil to sell it in northern nation of Gusteko. It once more proved his bad luck, as price of Iron skyrocketed after because of 'a noble' gathering weapons and border was blocked due to Royal Selection, almost ruining his business.
Elsa's might be a typical and short one.
Elsa was an orphaned thief on the street of Gusteko. In one day, she was caught by the storeowner, naked and about to be raped on a street
(She was more worried about freezing to death).
(Un)fortunately, she picked up the glass shard nearby and slashed his stomach open.
It is when she felt great pleasure from the warmth of guts and blood spilled on her body in freezing weather, which proved to be helpful for choosing her future profession.
