School Days - S1-E3
Continuity mistake: When Max is walking around the school grounds he walks up to man breaking a piece of wood. The man breaks a piece of wood and then bends down to pick up a new piece, leaving one on the ground. The shot changes and Max is standing there talking and the man breaks the piece of wood and bends down to pick up another one (which should be the last piece). However there is another piece left on the ground.
School Days - S1-E3
Revealing mistake: When Max is being attacked with throwing knives, one is thrown into the closet door. Watch closely; the wire used to guide the knife is visible.