1x11 - Ai Tenchi Muyo!

This episode features prominent references to Indiana Jones and the Raiders of the Lost Ark. Tenchi and Hachiko wander a cavernous warehouse full of booby-traps to gather resources for the upcoming Cultural Festival. According to Hachiko, a guidebook is needed to navigate it. The Science Club follows them and immediately get lost and end up running for their lives from a giant rolling iron ball. Tenchi and Hachiko also have to run and lose the guidebook.