[Katsuyuki012]

They are.

In the beginning the difference wasn't too big, Summer Again had ~220k after 36h vs Nonfiction's ~250k. But Nonfiction already had 500k views after 4 days vs Summer Again's 500k in 7 days.
Nonfiction probably did better since the video came out on release day + there was some more hype with how it got announced. I think the challenge definitely helped a bit, too.

I remember Ayu mentioning another challenge for the summer – I wonder if that's still gonna happen or if they scrapped the idea.
It could give the song a little push, although I do believe that Nonfiction just has a "certain something" – possibly the aesthetics since Ayu doesn't have anything quite like it in her videography. Plus, the "are you kidding me?" & "you're full of shit" lines definitely got quite some attention by fans, haha!

However, if the views remain steady then I'm sure Summer Again will reach 1M in the near future. At least I hope so!