1. where do I find the Sakura flower for Haru
2. How do I complete the temple puzzle, I have put 2 rocks into the canals and I have a third to push around downstairs, do I have to restart?
3. how do I continue with Mary?
You can find the Guide (Guided Walkthough) in the Help Thread here on Itch (one with the "sticky") or go to the Patreon Page and find the Guided Walkthrough (which I have been doing) and Picture Walkthrough (though this one has not been updated since 1.0, but recommended if you want pictures and not text). All 3 Questions are answered there.