Bloody Monday/WMG

Hibiki's Defrosting Ice Queen act is just an act.
She's been training to be the perfect spy since birth, and emotional manipulation is one handy tool. There's also the fact that she passed for normal before her cover was blown.
 * Her current behavior appears to be sincere, although she's a pretty good actress.

Hibiki is being sincere but after her defection becomes known she'll get replaced by one of her "sisters".
"'Hibiki'? I killed her 35 chapters ago."

Hansel is one of Hibiki's clone-siblings and Hibiki is Gretal.
Hibiki said her fellow clones looked alike; she never said they were all sisters.