Kitto, Sumiwataru Asairo Yori mo Ending (Spoilers)

[Xexac]

If the title wasn't obvious enough, if you haven't read this VN go read it first because it is an incredibly beautifully written story.

Saw some recommendations for this and decided to read it. Still new to untranslated VNs so there's probably bits and pieces I missed but overall I really enjoyed it, especially the second half of the second chapter (everything before that was a bit too slow paced/had too much SOL for my liking) and the third chapter.My main question was about Waka

Spoiler

 

and why she disappears at the end of the final chapter. My Japanese is still rusty but from what I understood from chapter three, the main characters were reincarnations of the characters from legend of Momiji/Kureha (Waka's mother), particularly Momiji's father (Sasa), mother (Hiyo), husband (Araragi(lol)), and the hero (Harutsuge).

It is mentioned that time has stopped for Waka in this chapter and seems to be hinting that unlike the others, she isn't a reincarnation but Momiji's daughter Tsunewakamaru herself (unsure about this) which was what I initially thought was the reason for her disappearance (with Sasa saving her and allowing her time to "start moving" again) but the final scene with her in the classroom thanking (what I'm assuming is) the school for going along with her wishes and the line saying that Yumemidori was going to disappear left me a bit more confused.

 

Could someone clarify what happens please? Or was the ending designed to be open-ended? If so I'd love to hear some other thoughts interpretations on it.

Edit: Another question, who painted the picture of the

Spoiler

Shikunshi shown at the very end?

 

[Clephas]

Added spoiler boxes.  Casual readers might decide to see what the thread is about despite the spoiler warning.