How about a Penis Festival?
There are giant penis-shaped seesaws that you mount to increase your fertility, your potency, or just your joie de vivre.
You eat dried sardines, a Japanese aphrodisiac, or penis-shaped sausages, ice cream cones, lollipops, and rice candy.
There are various heterosexual legends for the origin of the festival, the most graphic involving an iron-jawed demon that hid inside a woman and castrated any man who tried to have sex with her. Then the Steel Penis intervened, broke the teeth of the evil demon, and made the world safe for sex. It was probably a metaphor for venereal disease, and people still come to the festival to pray for protection or healing.
But today it's not for heterosexuals only; there are many gay and transgender people in attendance, and the Kanamara Matsurai has become a fundraiser for AIDS research.
The festival takes all day, but if you have time left over, visit the Kawasaki Daishi, an important Buddhist temple, or the Fujiko F. Fujio Museum, dedicated to the Doraemon manga and anime series (about a robot cat and his boy).
Also see the Penis Festival of Greece.