“Parallel universe” in Japanese
Short answer
Parallel universe in Japanese is “パラレルワールド” (parareruwaarudo). Full meaning: parallel universe, alternative reality, parallel world.
Other ways to say “Parallel universe” in Japanese
並行世界
heikousekai parallel world, parallel universe
異世界
isekai another world (esp. in fiction), otherworld, parallel universe, different-dimension world, isekai
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