Shimoneta to Iu Gainen ga Sonzai Shinai Taikutsu na Sekai

Synopsis

SOX receives an invitation to meet up at a hot springs resort in Nukumi. Tanukichi remembers an artifact passed down to him by his father. When they arrive at the resort, they are met by Gouriki and Anna. Later, they find Sophia's unconscious body where they are confronted by an ero-terrorist called Base Black. He reveals himself to be the one who gathered everyone to the resort. He then challenges them to a duel for the artifact through Yakyuken. Gouriki's loss and subsequent undressing stuns Base Black long enough for Tanukichi to retrieve the artifact. As Tanukichi and Ayame are riding the tram, Anna appears while climbing the cables to catch up to Tanukichi and causes the floor of the tram to collapse. The duo reach an old mansion and explore it, finding a mechanism that the artifact fits through. Kosuri and Otome catch up to them and help open the vault which contains a treasure of erotic sculptures and statues. They pledge that one day the treasure will be able to see the world again when the anti-profanity enforcement comes to an end.

(Source: Wikipedia)