Impregnation

A sex scene that results in, or is explicitly framed around, a character becoming pregnant falls under the impregnation tag — sometimes as the plot's central premise, sometimes as a strongly implied outcome. It's closely linked to nakadashi, since unprotected internal ejaculation is the usual mechanism a story uses to set up conception. Readers specifically drawn to pregnancy-focused storylines can browse impregnation hentai manga and doujinshi on Top Hentai's growing archive.