Hm...
I can think of 3 ways to go about this.
a) destroy the tree; we'd probably need Youmu's help for this. I also think it would most likely irrevocably kill Yuyuko.
Not a good idea.
b) try and see if we can really talk to Yuyuko. Approach the tree, touch it, evoke memories of things Yuyuko used and liked to do.
If it works, it would probably be the best way to do it. Could also result in us getting killed or absorbed into the tree.
c) Get the tree to envelop Youmu and us, like it did with Yuyuko. If Yuyuko still has some awareness left after getting
absorbed by the tree, so might we. This has an at least equal chance of us just dying and possibly sending
the tree into overdrive, though, so... Also, I don't know if that's something Yukari would actually do.
d) See if we can find anything related to the tree in Hakugyokurou first.
I'll go with b) for now, unless someone has a better idea.
>Remember time we've spent with Yuyuko.
>"It's been a while, Yuyuko. I would really like to drink some tea with you again. What were you up to while I was away?"
>"Do you remember me, Yuyuko?"
>You'd better do.
>While saying these things, walk up to the tree. Watch for any sudden movements or any effect the aura might have on us.
>If we don't get attacked or start having trouble with the aura, reach out and lightly touch the tree with one finger.
>"Hey, Yuyuko." Remember how Yuyuko looked like while saying this.