Set in an Eastern fantasy setting, Dān Fěi and her brother, guardians of a sword known as the Tiān Xíng Jiàn, are pursued by the evil Xuán Guǐ Zōng clan, who seek to obtain the sword for their master, Miè Tiān Hái. While her brother is defeated, Fěi, who possesses the sword's crossguard, escapes and finds herself in the care of the wandering swordsman, Shāng Bù Huàn, and a mysterious man named Lǐn Xuě Yā, who become her protectors from the pursuing Xuán Guǐ Zōng clan.

Kotetsushin Jeeg takes place fifty years after the original and features a new cast of characters—primarily the new main character Kenji Kusanagi, a high school student who becomes Kotetsushin Jeeg to fight the sudden reappearance of "Haniwa Genjin" ("Haniwa Phantom Gods", or clay robots) from the Jamada Empire ruled by Queen Himika. Other characters include Tsubaki Tamashiro (grandaughter of Miwa Uzuki); and Kyou Misumi. Other main characters from the original series also appear.

This anime adapts Key's visual novel Kud Wafter, which follows the romantic relationship between Riki Naoe and Kudryavka Noumi from the game Little Busters!

Hiroshima, summer of 1945. A young girl named Nobuko saves a starving kitten from crows. She wants to keep the kitten, but her parents dismiss the idea. Nobuko eventually convinces them to let her keep it. She and her brother Makoto name the cat Kuro. Kuro quickly brings joy and laughter to the family. As World War II takes its toll on Japan, it becomes harder for Nobuko and her family to care for Kuro. One August morning, Kuro begins acting strangely...