Interesting end-of-the world love idea, although quite exploited recently: I've seen at least 2 BLs with this kind of story lately.
Not bad acting.
The lead (Seto Toshiki) played already in another BL, he was blond there which I found awkward, but he is back to black now and sooo much better.
The second guy is suspiscious, sweet but there is something sinister about him. I don't quite trust him, and the way he pushed himself on Masumi, hmmm... it was kinda Valmont seducing madame de Tourvel!
The song at the end of the first episode so sweet , like a gentle lullaby. And I was pleased to hear a girl's voice which would not sound pretentious or 5 years old.
And the best thing: kissing. EVENTUALLY. Oh my goodness, dear japanese drama guys, we've been waiting for so long!
Please follow this path. You don't need to go too far, but keep going this way!
Thank you. <3