I admit, scoffed off you guys making assumptions of Katarina being Komori mother, but her hair color and background story does make her her biological mother... I'm more oblivious than Hiragi...
With all that Misunderstandings™ in previous chapters and finding solutions alone, glad author decided on lost art of Communication Is The Key, although entertaining to some point it's vexing to read...
I'm wondering what will be the solution, since Komori having sex with Hiragi will end up with them loosing contact forever and paying the price will end with an offer of her own life or at least part of herself like Katarina, but only for a tiny bit of forgiveness from the spirit she will make a contract...
Having sex with someone else is an option, but neither will accept it after they finally became a couple, although at first it was Hiragi selfish wish but eventually grew to true love.