"Wasei-eigo" presents more difficulties for Japanese and learners of Japanese as such words, once entered the lexicon, combine to form any number of potentially confusing combinations. For example, the loanwords "chance", "pink", "erotic", "over", "down", "up", "in", "my", and "boom" have all entered "wasei-eigo" lexicon, combining with Japanese words and other English loanwords to produce any number of combination words and phrases. 'Up,' or "appu", is famously combined with other words to convey an increase, such as "seiseki appu" (increased results) and "raifu appu" (improved quality of life). 'My," or "mai", also regularly appears in advertisements for any number and genre of items. From "My Fanny" toilet paper to "My Hand" electric hand drills, "mai" serves as a common advertising tool. Infamously, the beverage brand Calpis sold a product regrettably named "mai pisu" or 'my piss' for a short time.