None. Sometimes there are bathing scenes but they only last for a few seconds and show nothing.
A cat's non-detailed butthole is sometimes visible, marked as an X and with no sexual intent.
In one scene a girl warns a guy to not look at her panties while both are climbing up a ladder. Nothing sexual is shown, the girls are almost always seen wearing long dresses that reach the ankles, including in that scene. That only happens once in the whole series.
