Dual! Parallel Runrun Monogatari Special;  

Dual! Parallel Trouble Adventures Special, Dual Parallel! Trouble Adventures - Final Frontier, Dual! Parallel Lunlun Monogatari Special, デュアル！ぱられルンルン物語「ファイナル・フロンティア」, Dual Parallel! Trouble Adventures Special, Dual! Parallel Lunlun Monogatari: Final Frontier, Dyuaru! Parare Runrun Monogatari

The two planets have achieved peace and their inhabitants are living as regular citizens. However, life may not be entirely normal for war hero Kazuki who now resides with five beautiful women under one roof. It seems that he won't have to wait long before embarking on another adventure. An ancient artifact has been discovered which serves as a gateway to parallel universes. This time, Kazuki must prepare himself for an outer space journey.