Does this mean Sasaki to Miyano has ended in Japan or is it also still ongoing?

It's still ongoing, the author releases both of them at the "same time" (well not exactly, Sasaki to Miyano's releases get sometimes pushed back when the author work on this one, so instead of having a volume of Sasaki to Miyano every 6 months, we'll get less, but we'll have this one added)

Ah I see~ Thank you!