On the 10th day of every month, Junsuke Senoguchi has just one thing on his mind: the closing level of the Nikkei average.

That is because Senoguchi, an unassuming man in his late 40s, has built a machine that has been predicting the direction of Japanese shares, and once a month he gets a progress report on its success. The model makes a simple call — whether the equity index will be higher or lower after 30 days — and over almost four years it has been right 68 percent of the time.

"I'm so happy" when it works, said Senoguchi, a senior equity strategist at Mitsubishi UFJ Morgan Stanley Securities Co. in Tokyo. "It's because I feel I can predict the future."