'At all times be impregnable' - Osada Steve's shibari class

In the living room there are leather sofas, an aquarium, framed nineteenth century prints, tatami mats, an oriental carpet and a bamboo pole suspended from the ceiling. Back numbers of The Garden (the Royal Horticultural Society magazine) grace the bathroom shelves and outside there is an impressive array of plants. Today the speckled hen in the chicken run has laid a brown egg.

There are signs of pear rust and box tree caterpillar - a garden is a battlefield - but indoors all is calm at a Japanese rope bondage training session.

Osada Steve, a softly-spoken, deadpan German performer, photographer and film-maker, is conducting a private class for the initiated. The model for demonstrations is Sophie, a strong and graceful aerialist about the size of a sparrow.

Recollecting that the pursuit is based on a martial art, Steve's advice to riggers is 'At all times be impregnable' - watch posture and position so as not to be vulnerable to attack from the model. As if. He points out it's important to assess if a potential partner is going to say, 'Don't touch me, mother****er.' He is careful, throughout the two-day teaching session, to check that no one is feeling triggered.

On day two Steve interrupts me while I'm drawing (I'm triggered - don't talk to me, mother****er - but I remember my manners) to ask if I'm a dominatrix. The professional dominatrix in the room laughs, showing a surprising lack of self-control.

'We want to inflict pleasure,' he says. 'We want to provide the warmth and protection of rope to our rope partner.' He shows the model an apparent tangle of rope and flicks it out straight. It's a bit like being able to flip up a tennis ball between your shoe and the edge of the racket - you feel you could master the whole thing if you could do that.

For information about tuition please see shibariclasses.com