Two characters are about to kiss but then stop.

Aside from some very mild cleavage on one occasion (which is honestly more wholesome than suggestive), this anime is devoid of fanservice.

Some war action violence.

This movie's about as violent as Porco Rosso, except that there's blood on one occasion when a pilot is severely injured during flight in one intense scene. The plane sustains gunfire and a bullet grazes the pilot's head and shards of broken glass from the cockpit fly into the man's shoulder. Most of the blood is seen splattered on the cockpit window. Not as graphic as it sounds, but might be a little hard for children to watch. The man survives.

Mild language.

Profanity of the "d*mn" and "h*ll" variety (according to the English subtitles). Not frequent.

Some soldiers drink bear at a bar and are drunk.

The princess drinks and get drunk.

If this movie were to receive an official rating in North America, it would likely be rated PG for animated blood, brief mild language, and peril.