In the late summer of 2011, Rokudenashiko took a mold of her own vagina and started colouring and decorating the plaster cast. At the time, she was drawing a manga about vagina(Called MANKO in Japanese), but she was running out of ideas, so she thought, ”Let's try taking a mold of my Manko”, and as just taking a mold was boring, she tried colouring it in. From this point on, it became boring to just paint them and she started to play with them by decorating them with sparkles and dioramas, just like high school girls' deco-den.（The term DECO_DEN comes from the words ‘decoration’ and ‘denwa’(telephone). In this work, a diorama doll (sold in the plastic model corner of Tokyu Hands shop) is placed on top of the Manko to represent people enjoying themselves in the sea of labia, bathing in the sea. She enjoyed creating a story on her Manko, so she made several such works and called them the ‘Diora-Manko series.