Steins;Gate: Egoistic Poriomania is a oVA anime that premiered in winter 2012, produced by WHITE FOX.

About the production: the story comes from a visual novel, there is 1 episode of about 25 minutes and its current status is "finished".

Its main genres are comedy, romance and sci-fi, with themes such as Heterosexual, Tsundere, Male Protagonist and Chuunibyou.

On AniList, Steins;Gate: Egoistic Poriomania has an average score of 81%, a very good score, and appears on 117,464 users' lists.

The franchise continues in or follows from: Steins;Gate and Steins;Gate: Fuka Ryouiki no Déjà vu.

Special episode included in the last of the nine Blu-ray/DVD volumes. The story is set a few months after the last scene of the television series. On a calm day in Akihabara, Okabe and the other laboratory members are invited by Feyris to go to America. Mayuri and the rest are planning to reunite with Kurisu, who had come back to an American laboratory. A few days later, Okabe's mad scientist persona Hououin Kyouma arrives alone at the airport in Los Angeles, where he may be taking the first step to leading the world into chaos. (Source: Anime News Network)

Official synopsis from AniList.