I liked it! So here's one member of the Sasarai fandom not out your blood, Ina-chan! The idea is entirely plausible (a friend and I once discussed this as among the most reasonable pairings for Sasarai) and it added to my thoughts and feelings about Lena. I don't mention her much in my own writing about Sasarai because I'm not exactly sure I really understand her. But as you write her, I do like Lena a lot.
I also have to point out that I find that Yohan character rather interesting.