Here's the group with an all-English message (again with Aika's help) promoting "One and Only":
https://www.facebook.com/upfrontlink/videos/975445759181008Unlike the New York concert, Riho gets her English in without a hitch while Zukki and Fukuchan kinda stumble.
The title "Endless Sky" reminds me of Buono's "My Alright Sky":
Hopefully it'll have a similar sound?
Well, maybe not as soft, but another half-tempo hip-hop beat like "Egao no Kimi" would be really nice. Or just something funky and midtempo with the current EDM stylings (like "Funwari Koibito Ichinensei") would be preferred already.
"Tsumetai..." is listed third, so if Riho's getting a solo song it's likely to be that one. The title kinda fits in with her "hitorihoriho" gimmick.