Mami Fukuda and Yukari Nishiyama each shot a 5-under-par 67 on Friday to tie for the first-round lead at the T-Point Ladies.
Fukuda sank seven birdies against a pair of bogeys, one on either side of the turn, while Nishiyama carded a six-birdie, one-bogey round at the par-72 Wakagi Golf Club. Both players are looking for their first win on tour.
South Korea's Na Da-ye was a stroke back in third place at 4 under, while last year's tour money leader, Rikako Morita, Thailand's O. Sattaya and Hiroko Fukushima were a stroke further back in a tie for fourth. Last week's winner, Yukiko Ichinose was tied for 13th at even-par 72.
Sunday's winner at the ¥70 million event will earn ¥12.6 million in prize money.