TOKYO -- Lars Nootbaar's imaginary pepper-grinder was the talk of World Baseball Classic games in Japan, but the fun-loving gesture by the St. Louis Cardinals outfielder does not appear welcome in Japan's popular high school baseball tournament.

When a player for Tohoku High School twisted his two fists together -- imitating Nootbaar -- after getting on first base Saturday, the umpire told him to stop.

Hiroshi Sato, manager for Tohoku High School, defended his player. Tohoku lost to Yamanashi Gakuin Senior High School 3-1 at Koshien Stadium in Osaka.

"It's so popular the whole nation is talking about it," Sato was quoted as saying in the nationally circulated Mainichi newspaper and other Japanese media.

"The children are just having fun. Why do adults have to put a stop to it," said Sato, who played for Tokyo's Yomiuri Giants.

"We should be thinking more about how children can freely enjoy baseball."

High school baseball tournaments are extremely popular in Japan. Major leaguers Daisuke Matsuzaka and Hideki Matsui got their start in the tournament. San Diego Padres pitcher Yu Darvish, who is on Japan's team in the WBC, played for Tohoku.

High school baseball regulations tend to curb expressions of emotions, such as making a clenched fist after scoring.

"We have always asked high school baseball to abstain from unnecessary performances and gestures. We understand the players' feelings of wanting to have fun, but the federation believes the fun should come from the game," the Japan High School Baseball Federation said in a statement.

Taro Kono, who is in the cabinet of Japanese Prime Minister Fumio Kishida, raised the issue of the strict rules on a Twitter post. Kono was a leading candidate for prime minister when Kishida was chosen late in 2021.

Nootbaar's pepper-grinder imitation was a hit in Japan's five games at the Tokyo Dome, with television cameras often focusing on Nootbaar's teammates making the gesture, or his mother Kumiko as she watched from the stands.

Nootbaar was born in California and is the first to play for Japan's national baseball team by virtue of ancestry. His mother is Japanese.