pvccorsets

     The Japanese are getting a little soft.
    Two avant-garde Japanese designers, Rei Kawakubo for Comme des Garcons and Yohji Yamamoto, veered from their old tricks - asymmetrical hems, ragbag layers, somber colors and missing sleeves - in their spring '91 collections Thursday.
    Both showed a kinder, gentler side: long layers of sheer chiffon, silk and lace; crocheted capri-length catsuits under apron dresses; midcalf jersey sheaths and schoolgirl smocked and gathered shorts suits.
    Both collections ranged from the predictable black, latex pants,white and gray (dyed with sumi, a calligrapher's ink at Comme des Garcons) to the glare of Yamamoto's bright blue and green mod kimono pantsuits and crocheted jackets tossed over black capri catsuits.
    Even the popular print trend appeared in the Japanese shows. Comme des Garcons showed stained-glass mosaic and gemstone prints on sheer chiffon and silk jersey; Yamamoto stuck to brown and black polka-dotted silk.
    ''Because the times are so difficult,'' explains Marion Greenberg of Comme des Garcons, ''Rei decided to keep the collection very light, with a feeling of fantasy.''
    Frivolous nonsense, you say? Perhaps.
    But before you laugh off these flights of fancy, remember: Both designers were doing work-ethic aprons and overalls - seen in every Paris collection so far this week - two years ago.