Artist's commentary
"そ": At Someone's Mercy
Pronounced as "sojou no uo"... an expression for when you have no option but to resign to your fate and accept whatever the other person wants.
pixiv #31054662 »←"せ" "た"→pixiv #31127485 »
T/n: The title, "俎上の魚/sojou no uo", translates directly into "like a fish on the chopping board".