This paper analyses the views of 20 Japanese mothers concerning paediatric male circumcision and penile hygiene. In Japan, routine male circumcision has never been implemented for newborns and children, and adult males are mostly circumcised at aesthetic clinics. However, media reports indicate a trend of Japanese mothers willing to have their sons circumcised. In discussing penile hygiene and male circumcision, the construct of a 'sexual script' becomes relevant to understanding how linguistic and gender barriers made references to male genitalia and penile hygiene largely appear as 'vulgar' and 'unfeminine' in daily life conversations. Peers were often identified as the main source of information and only mothers who have struggled with their children's penile infections have learnt about male genital hygiene, a domain of knowledge largely transmitted by men. Male circumcision becomes a double-edged sword that could help prevent penile infections but also an embarrassing conversational topic that could elicit discrimination because most Japanese children are uncircumcised.