A Thong of Beauty is Japanese Forever

A very common theme in Japanese is "fan service", occasional peeks at girls’ undies which are usually quite innocent in context (perverts; American make everything overt).  Since these programs are aimed at after-school audiences, concentration on this theme can have both creepy, unsettling effects on normal (read: non-Japanese adult) people, or surreal, lyrical and delightful effects, depending upon context:

It’s a sweet song, about promises, unbearable things and the sun
shining through the window through which the singer sees the blue sea.  Many other (pithy and wittier) comments have been generated from this snippet of video.

This particular cartoon is in several parts, and can be seen at crunchyroll.com