wait, didn't Kaguya appear in reverse mamange too, living with Eirin?
A quick search doesn't turn up anything on danbooru. As far as I recall Eirin lives as a single parent just like Reisen.
Yeah, love at first sight... We didn't start dating until after I graduated, though...I look forward to guide you.Ah~! About my husband...Well, about that...We met when I was in high school--I will be teaching you Classic Literature from now on.What!? She was your teacher!?
