Crawl through randomly-generated dungeons to power up the weakest superhero in the world's history (you) and defeat the final boss threatening the Earth: Darkdeath Evilman! Customize everything imaginable, from your stats to your appearance; from your secret base to your theme song! Z. H. P. will scratch all your RPG itches!

In the year 20XX, Super Baby, a baby who is prophesied to save the Earth, is born. The people of Earth pamper it, but its sudden popularity causes it to be kidnapped by the monstrous Demon General Darkdeath Evilman. Darkdeath is then challenged to a fight by the Absolute Victory Unlosing Ranger, a supposedly invincible hero, to decide the fate of Super Baby and the Earth. The game begins with the original Unlosing Ranger, Pirohiko Ichimonji, oversleeping for his climactic battle and running late. As he rushes to confront Darkdeath, he is hit by a passing truck and killed. Before dying, Pirohiko hands his Morphing Belt to a random passerby, the Main Character, forcing him to inherit his title and duties. The new Ranger then arrives to fight Darkdeath Evilman as the people of the world watch on television, but he is promptly defeated. However, he is saved at the last minute by the World Hero Society and taken to the Hero Training Facility, a space station floating above Bizarro Earth. There he meets Pirohiko's ghost, who has become his guardian spirit, and Etranger, a cynical training instructor. Etranger immediately forces the Main Character to undergo training until he is strong enough to defeat Darkdeath, sending him on missions to help the people on Bizarro Earth and thus resolve personal conflicts of the people of Earth.