The entire universe is divided into the inner universe and the outer universe. The two universes are enemies of each other. The outer universe is ruled by demons, and the inner universe is divided into The Realm of gods, the Eternal Realm, and the Mortal Realm. In the universe, there are countless mortal worlds like the Tianfa Continent, and they are collectively referred to as the Jiutian Xin Region. In the field of Jiutian Xin, nine immortal emperors commanded all star fields in nine layers. Above the nine heavens is the realm of purification of immortal gods.

In a fantasy world where "jobs" are god-given from birth, heroes are born, not made—and Ein's job of "Appraiser" has put him about as far from the "hero" pedestal as possible. Used, abused, and eventually abandoned by his fellow adventurers, Ein decides it just isn't worth going on. Lucky for Ein, though, the end may just be the beginning, as well as a new lease on life. Turns out, his "worthless" job may just be the key to becoming a hero after all.

Lamune has returned to Earth with no memory of his adventures on Hara-Hara world and Doki-Doki space. The remains of Gobuhriki find their way to Earth, and awaken the spirit of Don Harumage. While Cocoa builds a fighting vehicle with stuff she finds around Tokyo, Milk and Leska set off to find Lamune and Da Cider to save the day before the new Gobuhriki is revived and destroys the Earth.

Lamune and Da Cider head off to Puff-Puff Palace to rescue two beautiful barely clothed maidens, Gold Mountain and Silver Mountain- the Mountain Duo. This of course infuriates Milk and Leska, who with a rather confused and unwilling Cocoa "transform" into "Seinaru Milky", "Seinaru Cacao", and "Seinaru Lemon". The three then head after their would-be boyfriends to extract their revenge.