Both dramas are set in the Qing Dynasty and adress the hardships and struggles of the palace life faced by women in that time period. Scarlet Heart is a time travel drama set in the reign of Kang Xi and we see Yongzheng rise to the throne. Ruyi is a harem drama set in the reign of Qianlong, son of emperor Yongzheng.
Both dramas adress the hardships and struggles faced by women in the jurchen/manchu culture. Rule The World is a time travel drama that covers the process of the foundation of the Qing Dynasty and Ruyi is a harem drama set in the reign of Qianlong, the sixth emperor of Qing.
Both drama have:
Palace intrigues, slow pace and
a storyline that covers many years of complicated alliances and enmities, rivalries and feuds.
Eripiyo is initially a woman leading a normal life until it is turned upside down after watching a performance of the minor idol group ChamJam, which leads her to becoming obsessed with one of its members, Maina Ichii. Despite Eripiyo's enthusiasm towards her, Maina is consistently the least popular member of the group, leaving Eripiyo to take it upon herself to buy a lot of Maina's merchandise, which mainly involves singles.
Due to her using almost all of her money to buy this merchandise, Eripiyo has only a single tracksuit she wears all the time. She frequently goes to ChamJam's concerts with her friends and fellow ChamJam fans: Kumasa, whose favorite is Reo Igarashi, and Motoi, who prefers Sorane Matsuyama. Eripiyo continues to work several part-time jobs to support Maina, and Maina herself increasingly becomes concerned that Eripiyo is pushing herself too hard for her.