Set 300 years after Utakata ni Warau, and 300 years before Donten ni Warau, during the Sengoku Period, it is the story of a young man who encounters a pair of Kumo family twins.

Year 252 M.C, in this era which plants are almost extinct and the land is barren, a strange disease developed. "Shinigami's flower," the unique lethal flower that carries death. The disease is curable if found in the early stages but if left till transformation stage it becomes lethal and the only option left is extermination. These are all dealt with by request to "Gokurakuen," the national medical institution specializing in dealing with shinigami's flowers. Our protagonist, Doctor Ichinose Souma is the class representative of Mobile Team Unit Class 1. Though as his class gets too few requests he and his assistant Hina often get into trouble interfering with other class's jobs.

(Source: MU)

In the eleventh year of the Meiji era carrying swords was forbidden by the government and those known as samurai were slowly fading away. However there were plenty that didn’t like those changes taking place in Japan and inevitably the crime rates increased. Japan’s only resolve was an inescapable lake prison. While the prison had no other way to access it but only through water, the 3 boys of the Kumo family were assigned to transport the criminals to their new “home”. Although... is that the only thing they were doing...?

Ayame longs to be a hero of justice, while enjoying life in Kyoto. One day, while coming back from dancing, she saves a mysterious man from a dog. The man drops what looks to be a game console. Ayame can't resist playing with it, but sometimes things are better left untouched...

Onigawara Hanasuke is dead. He only realized that when Mitamura, a dark haired glasses-wearing guy from another world, has confirmed it. The truth saddened Onigawa, but Mitamura offers to teach him how to revive himself. However, in exchange, he needs to help Mitamura find someone... and the time limit's seven days.
(Source: M-U)
Note: Released as three separate oneshots in Comic Blade Avarus.

Manji, the "murderer bodyguard" known as "Red Dog", joins Cards by chance and helps defeat Toys, a kind of playthings that kill. His weapon is a sword and his partner is Karu, a cold boy capable of transferring others' injury to his body. In one mission, Karu is wounded and his secret is exposed.
(Source: MangaUpdates)

Donten ni Warau side stories. Some of the stories take place before the main series and some after the end of the main series.