27. It's from one of the last few episodes when they're deciding on a new name, iirc.
But speaking of the film, it released August 22nd. I'm not sure if Crunchyroll will license it or not, but I'm really happy it finally released.
The manga has been getting a translation through SuBLime, and the first 3 volumes have been released with volume 4 releasing in November and 5 in early next year. Volume 3 more or less is where the anime stops, after Mafuyu and Uenoyama are officially dating.