on fire

idiomatic

Being burned by fire. / (idiomatic) Achieving good results at a rapid rate. / (idiomatic) Sexually aroused.

Japanese Meaning

火に包まれて燃えている状態（実際に火に触れて燃えている様子） / （比喩的に）非常に調子が良い、成功を重ねている状態 / （比喩的に）性的に興奮している状態

The old barn was on fire last night, and the firefighters arrived quickly.

昨夜、古い納屋が燃えていて、消防士がすぐに到着しました。

Sense（1）

Being burned by fire.

If the wind picks up and the flames spread, the whole town could go on fire.

Sense（2）

(idiomatic) Achieving good results at a rapid rate.

That striker has scored four goals so far - he's on fire!

Sense（3）

(idiomatic) Sexually aroused.