"InuYasha sighed, after yet another sitting"
Hee! I had to blink before I understood what you meant. I pictured Inuyasha at a sitting with tea and quilts.
Inuyasha's gratitute about meeting Kagome doesn't seem to match his frustration with his current situation. It would make more sense for him to be mad at her, even despite the sit-pain.
Saying "for" instead of "because" is a bit more old-fashioned than Inuyasha's usual voice is. The image of taking her out for a picnic is a bit OOC. If Inuyasha is to have a tender thought there, then perhaps he could remember having lunch with Kagome. That would make more sense.