A NATION where less than one per cent of the population is Christian, the Japanese are keeping Christmas well.

Charles Dickens and Nelman-Marcus would approved the goodwill and commer [WORD ILLEGIBLE] with which they pursue the sea [WORD ILLEGIBLE] December is a month-long binge of buying and celebrating that continues until Jan. 5 when the New Year's holiday ends.

Christmas in Japan has nothing to do with religion," explained Yukiko Maki, a 79 year-old retired businesswoman and wife of a former diplomat. "It's a children's[WORD ILLEGIBLE] with cakes and parties and presents. In Tokyo and in the small cities local churches sing "The Messiah" and carols.

Christmas became popular after World War II, first as a night club celebration, then in the homes. Japanese families have a feeling for its as a festival."

TOKYO IS A holiday town every day of the year. It is always outlined in lights and always decked out like a Christmas tree.

December, glowing neon, bright lanterns, bazaar-like shops with goods spiling into the streetsM flying banners coveredwuth a aroma of hot sweet potatoes and [WORD ILLEGIBLE] cakes blend naturally with Christmas sights.

On the Ginza, the department stores are lavish with pine trees, one four-floors tall, and wreaths, cotton snow, tinsel, and seasonal bargains.

Girls dressed in Santa Claus costumes sell-toys and junior executives on their lunch hour line up to play with the toys. Lush red poinsiettias and delicate pink and white cyclamen fill shop windows.

Plastic sprays of tinsel and colored balls hangs from trees along neighborhood streets. In Roppongi a florist shop os selling real Christmas trees to Japanese and foreigners for 3500 to 10,000 yen, about $15 to $45. KIddy Land, the giant toy store in Harajuku, tantalizesd with five floors of playthings.

Department store Santas are rare, but the plastic figures of Colonel Sanders in front of fried chicken shop is wearing a Santa Claus suit.

Bing Crosby's "White christmas" soothes the crowds near the Sony Building where bystanders near the seasonal animated display toss coins into the coffer for charity. The Japan Times, an English-language newspaper, is sponsoring a Wheelchair Fund for children.

THE CHRISTMAS season coincides with The Christmas season coincides with the the Japanese tradition of o-seibo, the custom of giving year-end gifts.

Before Christmas Week the Japanese housewife has bought o-seibo for the executives of her husband's company, for her child's teachers, for certain relatives, for anyone to whom the family feels obliged for favors done. Doctors, teachers of English, and the go-between who introduced the newly married couple are recipients of o-seibo.

Department stores sell gift boxes of fruits or fruit juices, sukiyaki beef or canned hot dogs, salad oil or sake.

According to a local newspaper column, the three favorite gifts are liquor, flavor-enhancers like dried fish or accent, and seaweed, a culinary delicacy of fried nori bits to use in cooking special dishes.

Some say the first gift housewives return to the store is the liquor. Others say it's the first one opened and finished.

While these gifts are practical goods in exchange for help or kindness to some Japanese Christmas presents mean only more money for the stores.

TO ME CHRISTMAS is nothing," said Satoko Iwasaki, 35, daughter of a Buddhist priest. "The Japanese people are victims of the department stores. They like to copy everything from the United States even though they don't believe in Christ or Christianity."

Mrs. Iwasaki, a teacher of English and wife of an engineer, was brought up in the precinct of a temple in Mia Predecture near Nagoya where her father administered to villagers and taught at the university.

She admits that her feelings come from her parents who disliked the commercial spirit behind Christmas. However, when the Iwasakis' daughter Rei was very young, they put up an "artistic tree," a small plastic repica, and gave her Santa Claus presents.

Mr. Iwasaki brought home a cake covered with stars and bells and a miniature Santa.Only last year when Rei was nine did the girl learn from school friends that Santa was her parents.

This year when the school winter holidays begin on Dec. 25, the Iwasakis will return to Mia Prefecture for New Year's festivities. Many Japanese go to their parents' home to celebrate the New Year as Japan shuts down for five days and then as the smog dissipate-one can see Mt. Fuji from the streets of Tokyo.