Do you need tickets for mokumoku Farm in Japan?

As shown in the figure, you need tickets to enter the farm area, but you don't need to pay after 16:00 every day (tickets are free after 15: 00 on weekdays, that is, Monday to Friday, which are not holidays).

The fare is 500 yen, and tickets are free for 0 ~ 2 years old.

But you don't need tickets to enter some facilities outside the farm, as shown below.