The number of women elected to the Lower House on Sunday fell to 38 — or 7.9 percent of the 480 members — after setting record highs in the previous two races of 43 in 2005 and 54 in 2009.
The decline was particularly noticeable in departing Prime Minister Yoshihiko Noda's Democratic Party of Japan, which saw only three female candidates win, down from 40 in 2009, after being pummeled in the general election.
The Liberal Democratic Party, which steamed to a landslide victory, saw 23 women win Diet seats, up from eight.
A total of 225 women ran in the election and 16.8 percent won seats.
The average age of the chamber is now 51.9, almost unchanged from the previous election.
Among them, 213, or 44.4 percent, had Diet seats when Noda dissolved the Lower House last month, and 83, or 17.3 percent, were previously lawmakers. The number of newcomers came to 184, or 38.3 percent, with 119 from the LDP. Only one DPJ rookie secured a seat.
The number of those who won after serving as mayors or local assembly members stood at 144, or 30 percent, followed by former bureaucrats at the national and local levels at 80, or 16.7 percent. Seventy-three former lawmaker secretaries, 45 people from the private sector and 21 lawyers also won Diet seats.
In addition, 148 so-called hereditary candidates — those whose relatives are or previously served as lawmakers — ran in the election, with 114, or 77 percent, winning seats.