How does the name Makoto translate into "Joker"? After watching the antics of this 14-year-old Japanese exchange student exchange student at a special ceremony at Challenger Elementary School to honor him and his classmates, no foreign-language dictionary was necessary.

Makoto Ohori and a new-found friend at the private Sandy school played discreetly with a skateboard Thursday while Challenger director Enid Lewis described the meaning of planting a tree and marking it with a stake that reads "Japan Day March 31, 1988."When the skateboard whipped out of control and headed off on its own, the pair shared a muffled laugh and then quickly refocused their attention. Standing a few feet away but also enjoying the ruckus was Ohori's sidekick, Yugo Twatsuki, 13, better known as "Crazy."

These monikers, given to them by Lewis as a way to make their personalities immediately known to Challenger students, are some of the English words they have picked up during their two-week visit to the United States.

While many of the questions about their stay had to be asked and answered through a translator, their new American names posed no language barrier. The pair, who had carefully considered questions about what they'd seen in Utah and how classes here compared to those in Japan, gleefully repeated the names several times to make sure it was clear which belonged to each.

"Me `Crazy,' " emphasized Twatsuki, who then jabbed Ohori and indicated "Joker" before both of them burst into laughter.

Fifteen students, ranging in age from 9 to 18, and two adult chaperones from Kakagamihara, Japan, have been the guests of the parents of Challenger students since their arrival on March 19.

They are visiting many of the same students who came to their community last summer as part of a privately funded exchange program. This is the first year that the Utah school has participated in the program, which began five years ago in other Challenger schools in the San Jose, Calif., area.

All but the two oldest of the Japanese students, both 18, attended sample classes at Challenger, with the oldest students visiting Alta High School. Ohori and Twatsuki pronounced their American counterparts as much more active in class than they.

"Kids here are eager to express their own opinions. If you go to Japan and visit schools, you notice that teachers keep students silent," they said through their adult chaperone, Hiroshi Yamashita.

The students, whose first visit to the United States will end April 4, probably had more fun comparing the quality of skiing in Utah to that available in Japan. According to Yamashita, "It's the greatest snow on earth in Utah," because it is much drier than the snow in Japan.

Thursday's tree-planting ceremony, which took place in a chilly wind, will serve as a permanent reminder of their visit. Each of the Japanese students took part, either by pouring some water into the hole dug for the tree, shoveling dirt or pounding the stake.

And, of course, it was Ohori and Twatsuki who answered the call for "samurais" and hoisted the heavy tree into the hole.