The ruling coalition in Japan's Lower House is facing a resounding defeat, and an opposition coalition government could be on the horizon.

This was made possible in part by Proportional Representation. Looking at the latest election data:

https://www.nhk.or.jp/senkyo/database/shugiin/00/tousen_toukaku_hirei.html

The ones with a white cell on the right column are PR representative-elects, and grey cells are the candidates that won their local district in a traditional tally.

One major beneficiary is the Japanese Communist Party (violet), who only won 1 race in the FPTP portion, but because they had sizeable supports nation wide, has 7 total seats at the governing table.

This doesn't only help 3rd parties. The incumbent (red) and leading opposition (blue) parties locked in dead heats in many races, have elected some candidates from the PR field. That way the voice of the group that made 2nd place are not fully lost on the final result.