Juicy new chapter. I wonder if Kaede (Momoko's brother) is adopted also? I suspect so. He at least isn't Kanzaki's son: Kanzaki isn't the kind of guy to run out on his family like that.
I don't know what Touko and Kanzaki's "secret relationship" was, but I think they were friends and had mutual respect for one another. He admired how she was a free spirit and cared for others even at the expense of her shot at Tokyo U (but let's face it: no way she would've passed the exam if her grades were that bad). She was glad he figured out what *he* wanted and followed his own path to become a teacher rather than a lawyer. I don't really see them as lovers.
Now I wonder how she died, orphaning her kids a second time. Momoko mentioned that she was a single mom... I suppose she could've been married and had Kaede, been widowed or divorced, then adopted Momoko later.
The plot thickens. Looking forward to the next chapter! I looked at the raws, but I can't read Japanese and only sort of know what happens.