In the context of SDMT-444, Oppai I Cup refers to a pivotal plot device that drives the narrative forward. The term "Oppai" is a Japanese slang term that roughly translates to "older sister" or "upper body," while "I Cup" likely refers to a specific storyline or arc within the franchise.
(often associated with the "S-Cute Digital Media" series), featuring actress Azusa Nagasawa Production Overview Title/Theme sdmt444 invisible girl oppai i cup azusa nagasawa 2