Kiro recalls something suspect.

6.36 Transcript
[Kiro: I always wondered why my parents had specifically adopted a child from the Institute.]

Kiro’s dad: Kiro is no blood relation. And besides, you’re the one who said you didn’t believe in any family curse.
Kiro’s mom: True, but I can’t just stop thinking about this.

Kiro’s dad: She’ll be all right, as long as we raise her right.
Kiro’s mom: I suppose I’m the one who married somebody with a family history of mysterious disappearances.

[Kiro: Huh, wait!]