The yuri's been there since the beginning. It was only occasional bouts of Tomoko perving out at first, but she's always been gay for Yuu. If you go through the TVTropes page on the subject, you can see the subtext ramp up over the course of the series.
The last part of the first field trip arc (begins at chapter 69) is where the yuri really starts to kick in. Tomoko's relationship with Yuri Tamamura doesn't enter subtext territory until a bit later, but there have been a few notable moments in recent chapters.
Also this manga should probably be uploaded here.
Unlikely, as the series has been officially licensed for English release. You can buy the first 10 volumes in English on Amazon.
last edited at Apr 18, 2018 6:45PM