Suzumi-bune

The story begins in the Edo period with two foolish woman at the start of Kanda River's Kawabiraki, a festival marking the start of the boating season. A woman looking to be the daughter of a large shop gets lured over by a seemingly good looking man that appears and gives into pleasure. However, on the verge of the act, she is spotted by a boatman and falls into the river. The other woman, who looks like a mother, beckons the boatman to have the daughter make love again as she peeps. Please do not upload or approve any images to this entry.

Referred to be the first hentai anime, it was made in an Ukiyo-e type of animation style.