Every now and then, a work comes along to remind you that, for some couples, physical pain is a good thing. Love, in their case, is not expressed so much with diamonds and flowers - but with slaps, kicks and bruises.
But please don't choke on your coffee. Judging by the romance of Shun-kin and Sasuke in the stage adaptation of Junichiro Tanizaki's 1933 story of Shun-kin, a sadomasochistic relationship may be no less pure, happy and enduring than an old-fashioned marriage.
Of course, S&M is not a new topic on the page, stage or screen. In the last century, the controversial novel Story of O (1954), the Japanese screen shocker In The Realm of the Senses (1976) and Marlon Brando's Last Tango in Paris (1972) are just a few among many works to celebrate the idea that love and desire are more perverse than conventions would have you believe.
More recently, there was the sensational, if poorly written, bestseller Fifty Shades of Grey - whose title, incidentally, would have been a great alternative to Shun-kin.
For throughout the two-hour production by Complicite in collaboration with Setagaya Public Theatre, much of the stage was engulfed in eerie, claustrophobic darkness.
At times, one had to squint through various penumbras to follow the tale of a beautiful, blind shamisen player, Shun-kin (Eri Fukatsu), and her devoted manservant Sasuke (played by three different actors).
Set in 19th-century Japan, the story centres on the vain and arrogant Shun-kin who develops a passion and scorn for her humble manservant Sasuke.
Gradually, she acquires a taste for striking him when she is displeased. Though they never marry - he is socially beneath her - their unconventional affair continues for decades.