The two young men have affected the sunglasses, spiked hair and garish clothing of “chimpira”, the lowest-level of Japan’s gangsters, and are stomping around the theme park looking for a spot of fun. They spot a young couple, arm-in-arm, and see their chance. One of the thugs reaches out to lay his hand on the woman’s shoulder and - ignoring the boyfriend and encouraged by his side-kick - tells her how cute she is. He may not be the most physical of specimens, but the boyfriend bristles at the thugs’ comments and steps forward. The hood throws a punch that the boyfriend slickly avoids before unleashing a barrage of fists that quickly has the trouble-makers beating a hasty retreat. Her honour defended, the woman fairly swoons at her lover’s demonstration of manly devotion to her well-being. And if he is wise, he will never let on to her that it was all a put-up job. Hirakata Park, a theme park on the outskirts of Osaka, this week introduced a service that it is describing as a “new-style flash mob” designed to help a man impress his partner. The service is free of charge and anyone can select one of a number of different performances through the park’s web site. The “Protect your Beloved” option is likely to be popular with anyone keen to show off their bare-knuckle fighting skills - whether real or imagined - while other scenarios include being roped in to defuse a bomb that is about to explode or giving blood to prevent another park visitor from expiring. The park suggests that anyone booking the performances - which are, of course, equally available for women to impress their significant others - not inform the person or people they are with of what is happening. One obvious drawback, however, is the possibility of another equally unaware park visitor stepping in to help out a wannabe-hero and stealing his glory.