It's pretty clear from this series that marriage has has done rather little to loosen Kaga up or improve her ability to express herself openly. I can honestly see her thinking using his name too casually is still somehow overly familiar, despite the fact they're married.
Or you know the artist just didn't want to commit to an actual name for him, but also didn't think her calling him "admiral" in personal writings would make sense with the fact she's shy and demure enough that using a personal euphemism to refer to him wouldn't seem entirely out of character merely being a nice smokescreen.
Kinda bugs me that Kaga calls her husband "that man". Sounds so impersonal.
It can have a very personal connotation in Japanese and Korean.
4/20
As always, my cooking was praised by that man.What sort of memo is she jotting down...?What's this? A diary...?No, it doesn't make sense for her to have been keeping up with such a thing...Zuikaku dropped in on Kaga's home.4/13
That man and I came up an auspicious sign together.