It's that time of year again. No, not the start of baseball season. Not the April end to March Madness either.

We're talking about the Festival of the Steel Phallus (Kanamara Matsuri) in Kawasaki, Japan.

Sunday's festival (see photos below) allowed revelers to celebrate all that is penis. And don't worry, Mom, those penis lollipops for sale were for a good cause: raising awareness for HIV prevention, according to reports.

Revelers in the streets paraded peen-shaped Shinto shrines called "mikoshi," emphasizing the spiritual roots of the schlong-a-thon. The festival's inspiration reportedly goes way back. In the 17th century, a 1-meter "Steel Phallus" was reportedly erected by a local blacksmith that honored Shinto deities of fertility and childbirth. Prostitutes were believed to have prayed there for protection from sexual diseases.

Nowadays, "People come to pray for good fortune and to ask the gods to protect them," Hiroyuki Nakamura, a local priest of the shrine, told AFP. "The festival is steeped in the past but still has a valuable part to play in modern society."

According to Metro UK, visitors on Sunday also sported giant penis purses and even "straddled a giant wooden phallus." Hey, what's a street fair without rides?

Penis festival highlights:

TORU YAMANAKA via Getty Images People crowd outside the Wakamiya Hachimangu Shrine to see portable shrines bearing phalluses during the Kanamara Festival in Kawasaki, a suburb of Tokyo, on April 3, 2016.

TORU YAMANAKA via Getty Images The festival has been held since 1977 but its inspiration, the Steel Phallus, dates back to the 17th century.

TORU YAMANAKA via Getty Images Women hold penis-shaped candy, among the many phallic edibles and souvenirs sold, at the Wakamiya Hachimangu Shrine.

TORU YAMANAKA via Getty Images Are those carved radishes in your hands or are you just happy to be at the festival?

TORU YAMANAKA via Getty Images Nothing like a treat during a festival.

TORU YAMANAKA via Getty Images Proceeds from phallic treats and other souvenirs went to HIV research.

TORU YAMANAKA via Getty Images Phallic shrines paraded through the streets are one of the highlights of the festival.

TORU YAMANAKA via Getty Images Worshipers perhaps can't help but think pink while accompanying this portable penis shrine.

TORU YAMANAKA via Getty Images Thousands attended the annual rite, which was held Sunday in a Tokyo suburb.

TORU YAMANAKA via Getty Images Thousands attended the festival, which also featured people carrying penis purses.