Alternate 23rd episode of Steins;Gate, which leads into the story of Steins;Gate 0. It was included with the Steins;Gate Complete Blu-ray Box.

Tanya Degurechaff is a young soldier infamous for predatorial-like ruthlessness and an uncanny, tactical aptitude, earning her the nickname of the "Devil of the Rhine." Underneath her innocuous appearance, however, lies the soul of a man who challenged Being X, the self-proclaimed God, to a battle of wits—which resulted in him being reincarnated as a little girl into a world of magical warfare. Hellbent on defiance, Tanya resolves to ascend the ranks of her country's military as it slowly plunges into world war, with only Being X proving to be the strongest obstacle in recreating the peaceful life she once knew. But her perceptive actions and combat initiative have an unintended side effect: propelling the mighty Empire into becoming one of the most powerful nations in mankind's history. [Written by MAL Rewrite]

Taking place in the past it offers a view at the Saiyuuki quartet before their formation and their journey to the west. First OVA starts with Sanzo and his master, also with Ukoku (known as a later Ni Jianyi). Second OVA shows first meeting of Goku and Sanzo. Third OVA considers the events after Hakkai's sins and his trial (that we know from first season of "Saiyuuki") and his decision to live in Gojyo's house.

As always, Shi Miao is tired of her brother's ridiculous antics, and Shi Fen can only hope to escape the clutches of his violent sister. With their friends and classmates in tow, the two continue their dysfunctional relationship as reluctant but devoted siblings. [Written by MAL Rewrite]