^ I was also very impressed by the performance. I liked the song before (hearing it from concert audio recordings), but to actually see them perform makes it so much better.
That solo line from Mizuho stood out to me, too. It reminded me of the singing by Sakura and Masaki when they use their deeper voice.
I also noticed a cool (but short) solo line by Saori.
The choreography and their expressions have improved so much.
Hatsukoi Sunrise live performance (Youtube):