One of my younger cousins, aged 23, managed to pull off what he calls the kotoshino igyō (今年の偉業, the great accomplishment of this year).
In case you're wondering, this has nothing to do with nuclear reactors or government reform. A sōshoku danshi (草食男子, herbivore male) with wrists and ankles like matchsticks, this cousin was invited to be the sole male member of a joshikai (女子会, girls only party), all expenses footed by the joshi (女子, girls), their ages varying between 28 and 34. According to my cousin, the ladies were typical nikushoku joshi (肉食女子, carnivorous women) who pulled his hair, told him what was wrong with his wardrobe, probed incessantly about his sex life and kept him drinking until the wee hours. He's still recovering from the experience, and said to me (coughing a little): "Shōganaiyo, anoyoru boku wa petto mitaina mono dattakara" (「しょうがないよ、あの夜ぼくはペットみたいなものだったから」"It can't be helped because that night, I was like a pet)." Maji (まじ, really)? Elsewhere in the world, pets are treated with more respect.
The joshikai-plus-one is a nifty invention and the joshi that plan these events usually like to make sure the additional male is of the young and adorable variety. Even better if the boy is susceptible to seduction and unoffended by the inevitable ijiritaoshi (いじりたおし merciless poking fun) that add extra zing to these gatherings.