The 2007 and 2011 tournament winner has a one-stroke advantage over compatriots Ai Suzuki and Miyuu Yamashita.
The 19-year-old became the youngest winner of the JLPGA Championship Konica Minolta Cup, earning the title with an 8-under 64 in the final round.
Inami has won four of the eight JLPGA Tour events since early March, including last weekend's Fujisankei Ladies Classic.
