The Liberal Democratic Party (LDP), led by Prime Minister Shigeru Ishiba, and Komeito, its junior coalition partner, won 215 seats in the lower chamber of parliament. A majority requires 233 MPs.
The Constitutional Democratic Party of Japan (CDPJ), the biggest opposition party, increased its number of seats from 98 to 148.
The parties now have 30 days under the constitution to attempt to create a coalition administration. Days or weeks of political wrangling may lie ahead.
In the weaker upper chamber, the coalition led by the LDP still holds a majority.
Mr. Ishiba, who took office as prime minister less than a month ago, has suffered a significant blow as a result.
The political risk that Mr. Ishiba took by calling a snap election has backfired. His party has been severely undermined.
Widespread public dissatisfaction with Japan’s stagnating economy and resentment at the ruling party’s handling of a corruption scandal accompanied the election.
“The results so far have been extremely severe, and we take them very seriously,” Mr. Ishiba said to the public broadcaster.
