Money leader Sakura Yokomine matched the day's best score to jump into a share of the lead after the second round of the AXA Ladies on Saturday.
Yokomine shot a 6-under 66 to tie South Koreans Kim So Hee and Shin Hyun Ju for the lead at 8-under 136 at Tomakomai Golf Resort 72 Emina Golf Club.
The 23-year-old perennial title contender had an eagle, five birdies and a bogey in a bid to become the first player to win four events this year. Kim shot a 67 and Shin carded a 70.
Sitting one stroke back are Miho Koga (68), Shin Ji Yai (68), Momoko Ueda (69), Shiho Oyama (69) and Lee Ji Hee (71).
Overnight coleader Yuko Mitsuka dropped into a tie for 17th at 4-under after a 74.
Defending champion Shinobu Moromizato rebounded from an opening 75 to shoot a 66 and share 24th at 3-under.