For centuries, a god named Celestin has been imprisoned on the moon for betraying the kingdom of Yggdrasil. Released by the fairy Morgan Le Fey, Celestin travels to Earth to reunite with his former pupil, the goddess Belldandy. Things go awry as Celestin erases Belldandy's memories of her boyfriend Keiichi and uses her as a catalyst to wreak havoc on Earth and Yggdrasil.

Legends tell of an invincible martial art known as Mutsu Enmei-Ryu, an unarmed style that allows the user to defeat any number of armed opponents using incredible speed and strength. This is the story of three generations of those who bear the name Mutsu, and their encounters and battles with the strongest fighters of their era.

Hiroki Fujisawa and Takuya Shirakawa harbor admiration for two things in their life: their classmate Sayuri Sawatari and the vast Ezo Tower that stands boundlessly across the Tsugaru Strait. Fascinated by the limitless structure beyond their reach, Hiroki and Takuya begin constructing an aeroplane from a fallen drone they discovered—naming it the Bella Ciela—to fulfill their dream of one day reaching the sky-scraping top of the tower. Later joined by the girl they love, Hiroki and Takuya promise Sayuri to fly with her to the seemingly otherworldly top together. However, Japan has suffered a North-South partitioning that has fueled conflict near the base of the tower, which marks the border between the America-controlled Southern islands and the Northern lands occupied by the Soviet Union.

Further along, Sayuri suddenly disappears, and Hiroki and Takuya never see her again. Unbeknownst to them, she fell victim to a sleeping disorder that left her comatose for the past three years. Although Hiroki and Takuya later learn about Sayuri's condition, they also discover that the girl's unconscious state is oddly linked to the same tower the trio had promised to conquer together.

[Written by MAL Rewrite]

Aikawa Ayumu was revived as a zombie by the cute necromancer Eucliwood Hellscythe. After the zany, madcap adventures in the first season of Is This a Zombie? ended, Ayumu thought his life might finally get back to normal, or as normal as it can be for a zombie. However, destiny has other plans for him. Some guys just can't catch a break. (Source: FUNimation)