Artist's commentary
Inazuma (32, 8th week of pregnancy) and Koyayoi (18)
(Sorry, here's an explanation) This is seven years after the story of 32 years old Kisaragi. This is also three weeks before Inazuma's coming out with her pregnancy. That last part is her thinking, "But even Ikazuchi doesn't realize it..."
It's shameful that I can't just make the picture speak for itself without explanation.