with a bang

figuratively informal

(informal, figuratively) Flamboyantly; in a noticeable and exciting manner. / (informal, figuratively) Suddenly serious or down-to-earth.

Japanese Meaning

華々しく、目立つ、興奮させる様子で / 突然、真面目になって現実的になる様子

She ended her speech with a bang, leaving the audience cheering and laughing.

彼女はスピーチを華々しく締めくくり、聴衆は歓声と笑いに包まれた。

Sense（1）

(informal, figuratively) Flamboyantly; in a noticeable and exciting manner.

go off with a bang

Sense（2）

(informal, figuratively) Suddenly serious or down-to-earth.