Since you said nothing, I shall answer the Yuuka one. (At last.)
First, greet her with the politeness and respect she deserves. Ensure her I mean no harm in her or her flowers and offer to drink with her. From there on, it would be learning about what actually happened during the Reimu/Marisa Mansion Invasion, how she is with Elly, the Mansion itself and if she still goes there, what is was like in Makai, etc, etc.
And so, you encounter Tewi. Will you plant a trap or two?