Ikeda has won 14 Japan Tour titles and Tanihara 13 while Kataoka has just one victory although all three have been in fine form this season with Tanihara leading the money list, Ikeda 3rd and Kataoka 11th.
Australian Matthew Griffin worked himself into contention with a second round of 67 to be in a share of 5th place and four shots from the leaders.
Griffin is chasing his first Japan Tour title although he has won events on the One Asia and Australasian Tours including when successful earlier this year at the New Zealand Open.
Of the other Australians Won Joon Lee is 32nd and Scott Strange 42nd.
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