I think this was pretty explicitly going to be a yuri manga and not a subtext manga from the start, I dunno why anyone had doubts otherwise.
https://dynasty-scans.com/chapters/pocha_climb_ch03#31
https://dynasty-scans.com/chapters/pocha_climb_ch04#7
Or rather, with these panels, I'd say it's already objectively not subtext (even though they haven't held hands yet). The whole thing with subtext is that the possibility of romance between girls is never raised; the author just pretends such a concept doesn't exist. Hence why you have to read into the subtext, since the actual text doesn't mention it. But here you have Aira already thinking she wants to date Tsugu while imagining kissing her. That acknowledgment alone puts it into explicitly gay manga territory, no reading between the lines necessary here.