Just a quick one and confirms something I already knew but it's good to have extra proof.

Kanao LITERALLY calls Kanae her sister when introducing herself to Douma.

Kanae canonically adopted her into the Kocho household. Kanao appears as an adopted sister alongside Kanae and Shinobu in her databook entry. So obviously she can 100% truthfully claim to be Kanae's sister.

But calling her "Kanae-san" is crazily inappropriate for their relationship. That's a polite address you'd use for strangers, co-workers you don't know that well, very lose "friendly" relations, etc. The NORMAL address would be "Kanae-oneechan" or simply "oneechan", or even "nee-chan / -san like Shinobu does. On the outside case just the name without the honorific could work. But "Kanae-san" would never be used in normal circumstances.

What's going on? First, the panel itself is a hint. "On the brink of death Kanae-san said". WHAT she said isn't even in the panel. The bubble in the center, the main focus, is what's this panel is about. Attention is being drawn to this.

Now consider what we recently found out how Kanao CAN'T disobey orders. This suggests that Shinobu's rejection of Kanao as Kanae's sister WASN'T just a passive one-sided thing Shinobu held on to (ie, saying "I'll tell you about the demon who killed MY elder sister"). She ORDERED Kanao never to use familial forms of address. Or she ordered Kanao never to use such addresses to HER, which means Kanao is specifically telling Shinobu that she KNOWS she's listening.

Interestingly, no matter how much Shinobu loathed her and wanted to see her gone, she DIDN'T take the coin, hairpin or memory box, all things given by Kanae.

Kanao hidden plot update