Gut reaction to this is that it's making a mistake in trying to keep the heroine "(shoujo-)normal" and the guy kinda grounded. I get that it's going for a "teasing a cat you're playing with" vibe where the relationship she wants is constantly dangled juuust out of reach and jerked away when she dares to hope for it.
But pairing her honest affection with his spectrum-y "does he mean it or does he not" feels a little too real and too cruel for me to even smile at.
If she had a similarly cynical reason to be engaging with him, like morbid curiosity, or if she were an unsympathetic yandere dirtbag pretending to be normal and ruining his "lesson data," it would hit better. Similarly, if he were even crazier, the action bigger, or he only viewed the world through romcom tropes or something, I think you could get away with having her be normal-ish.
But trying to walk the tightrope of narrow plausibility like this is risky, because people might kinda check out, emotionally, at which point all you're left with is a very compromised comedy.
Hope I'm wrong and it hits its stride.