Both of them supporting the other while also giving them an "out" in order not to make them feel more uncomfortable by being vulnerable is incredibly cute. And that from two people who are this blunt, too.
Of course, Sayuki did steer herself right into a miscommunication because of this too (and just believing in that blatant lie is also a factor here, but that's a Sayuki Classic), and there is definitely also an element of conflict avoidance to it, but it's still... interesting.
I'm also curious if she will further ruminate on the entire shrine thing later, or if this really already was the extent of her reaction to it. "Just another Touma Sera thing", or something along the lines of it.
It would be a bit worrying honestly if she didn't really care too much about this.
Also, I do hope she doesn't just let it slide, for Sera's sake too.
It feels like she really just showed it to Sayuki because she felt incapable of bringing across her feelings for her in any other way.
There also was a certain line she said: "I feel as if I'm seeing who you really are."
Which mirrors what that director from the previous chapter (possibly Sera's father) said about Sayuki in her role as "Repi" too: "She was just being herself."
Sera seems to want exactly that.
Somebody with whom she knows what she is at.
Like the ever-earnest Sayuki.
Of course, why it would have to be her, why no one else would do, why she felt like she needed such a person in her life at such a young age already - all of those are interesting questions I really am looking forward to getting answers to.