Yesterday was not a typical day in Room 5, the Japanese language classroom at Bethesda's Walt Whitman High School.

The crown prince and princess of Japan were sitting next to the chalkboard. A row of solemn diplomats stretched across the back of the room. An entourage of Japanese reporters and photographers were leaning over the partition of cubby holes, straining for each royal word and gesture. U.S. State Department security men with coiled radio cords running from their ears and into their shirt collars were methodically scanning the room.

There they were -- Prince Akihito, who will inherit the largely ceremonial throne from his father Emperor Hirohito, and his wife Princess Michiko on a six-day visit to the United States -- listening to a mock telephone conversation between students and a teacher, demonstrating the grammatical constructions: "I am supposed to do something" and "I plan to do something." Back and forth, the students and their teacher -- Taeko Wu -- lobbed seemingly flawless syllables of Japanese.

Although other schools in the area teach Japanese, Whitman's Japanese language program, according to Jean Morden, the head of the school's foreign language department, is the largest in the continental United States. About 100 students are enrolled in Whitman's four-year Japanese program.

As Akihito and Michiko sat on two red chairs facing the students, the class led off with a rapid fire drill of Japanese characters: Morden asked the students to identify each of the 38 characters tacked on the bulletin board, then form a sentence with each Japanese character. The students either recited a Japanese proverb that contained that character or formed questions that could be answered using that character.

Not once did a familiar word of English make its way into the room.

Two students -- Diara Holmes, a second-year student of Japanese, and Sam Gafsi, a fourth-year student -- were asked to introduce themselves to the prince and princess. Holmes talked about a visit to Japan last summer, her studies of the French and Spanish languages, and her plans to attend Brown University or Harvard. Gafsi, a 16-year-old senior, also told the couple of his visit to Japan and his plan to study Japanese in college.

Another student, David Ripin, gave the couple a book made up of Japanese compositions from last year's third-year students.

When Prince Akihito accepted the book he told the students how surprised he was at their ability and playfully tested their comprehension by reciting a haiku -- a Japanese poem -- he had composed about a turtle.

The class was preceded by a 20-minute ceremony on the playground of the nearby Whittier Woods Elementary School, where the couple was serenaded by Walt Whitman's pompon squad, wiggling and waving their pompons to the raucous loud-speaker sounds of a rock song. Then came a performance by the school's marching band and a presentation of two Walt Whitman 25th anniversary T-shirts for the prince and princess.

The couple gave a book and videotape of Japan to Morden, one of the school's two teachers of Japanese, and to Walt Whitman's principal, Jerome Marco.

Akihito told the gathering of about 300 students, teachers, parents and members of the local Japanese community, that the visit reminded him of his own "good old days of high school."

Akihito, relying on an interpreter, said, "Some of you might become experts in the Japanese language after your high school studies, but even if you don't become an expert, your studies will make you include in your vision the Japanese country for a long time."

After their visit to Walt Whitman High, the couple stopped at the Washington Home, a hospice in Northwest, where they greeted patients. Akihito later met with editors at The Washington Post and toured the newsroom.

The prince's afternoon concluded with two sets of tennis at Vice President George Bush's residence. Akihito teamed up with tennis pro Pam Shriver, beating Secretary of State George Shultz and Bush, 6-2 and 6-1.