Wo Wei Ge Kuang: Xuanlu Chongqi

If time did not allow ordinary things to be ordinary. How would you have lived? It is the Bakumatsu and early Meiji Period. Akizuki Keiichirou and Kusaka Touma stand of opposite sides of the political scale of the time but still, something as fragile as the shell of a cicada binds these two men together in a tragic and cruel fate. A story of friendship, love and seperation as well as reunion and sacrifice. (Source: AniDB)

This is a special to To Heart: Remember My Memories, which includes fighting scenes between all the female characters.

The Amanto, aliens from outer space, have invaded Earth and taken over feudal Japan. As a result, a prohibition on swords has been established, and the samurai of Japan are treated with disregard as a consequence. However one man, Gintoki Sakata, still possesses the heart of the samurai, although from his love of sweets and work as a yorozuya, one might not expect it. Accompanying him in his jack-of-all-trades line of work are Shinpachi Shimura, a boy with glasses and a strong heart, Kagura with her umbrella and seemingly bottomless stomach, as well as Sadaharu, their oversized pet dog. Of course, these odd jobs are not always simple, as they frequently have run-ins with the police, ragtag rebels, and assassins, oftentimes leading to humorous but unfortunate consequences. Who said life as an errand boy was easy? [Written by MAL Rewrite]

The story takes place in Japan. The year is 2030 and Earth has been completely overrun by a viral disease named "Gibia" that turns infected people into various different monsters, based on their age, sex, and race. A samurai and a ninja from the early Edo period travel together through time and arrive in a ruined Japan to aid a professor working on a cure for the virus. Together, they fight countless Gibia monsters, outlaws, and other fierce foes on their journey to save mankind.