Yuka Saso carded a 1-under-par 71 for a share of 24th place at the start of the 4th Toto Japan Classic Thursday at the Seta Golf Course in Shiga Prefecture.
Saso, who is in her first stint at the LPGA of Japan Tour since the Tokyo Olympics last August, fired four birdies against three bogeys to trail solo leader Sakura Koiwai by six strokes.
The 20-year-old Fil-Japanese, who also seeks to eclipse her runner-up finish in last year's edition, shot four birdies against a lone bogey on No. 3 after 10 holes, before stumbling with two more bogeys on the 14th and 16th.
Koiwai, who was ranked 68th in the world, made her title campaign felt by firing a 7-under 65 highlighted by eight birdies and a lone bogey on the par-4 second hole.
Sumika Nakasone and Ayaka Watanabe trail by two strokes with similar 67s, followed by Nana Suganuma, Momoko Ueda, Ayakara Furue and Suzuki Ai with identical 68s.
Defending champion Jiyai Shin struggled early with a 2-over 74 at joint 58th following three bogeys and a lone birdie on the first hole.