若宮八幡宮, Shinto shrine in Japan

Wakamiya Hachiman Shrine is a Shinto shrine in Asahi-machi, Okazaki. Nobuyasu, eldest son of Tokugawa Ieyasu, is venerated here as the shrine deity, while his mother Tsukiyama Gozen is honoured at a separate Shinmei shrine. Beside the main hall stands the mound where Nobuyasu's head was buried in 1579, marked by a pine planted on Ieyasu's orders.

In 1579 Matsudaira Nobuyasu, lord of Okazaki Castle and eldest son of Tokugawa Ieyasu, was forced to commit suicide at Futamata Castle on suspicion of colluding with Takeda Katsuyori. His head was returned to Okazaki and buried at Nemoto-Ishihara, in present-day Asahi-machi, where a pine was planted as a marker. In 1580 Ishikawa Kazumasa, the castle keeper, built a mound over the head, and Nobuyasu was enshrined here as Wakamiya Hachiman, his mother Tsukiyama Gozen at a separate Shinmei shrine.

Locals have long visited this shrine for prayers and traditional festivals that mark its ties to the Tokugawa family. The site remains a spiritual center where community members gather to honor the past and participate in seasonal observances.

The shrine stands in the Asahi-machi district of Okazaki, a short walk from the nearest bus stop, and the grounds are open freely without charge. The main hall was rebuilt after the 1945 air raid, and Nobuyasu's head mound lies beside it, so allow time to walk the whole compound.

Unexplained phenomena were reported in the castle after Nobuyasu's death, interpreted as his presence lingering. These events led to veneration at this site, where visitors today can sense the tension between historical tragedy and spiritual respect.