いきなり (translations)→ beginning bluntly directly fast freely impulsively instant instantly leap new out-of-the-blue outright point-blank pointblank promptly sudden suddenly unannounced violently
さっさと (translations)→ briskly early immediately just pronto quick quickly simply soon thoughtlessly
さっと (translations)→ brief briefly casually effectually fling lightly rapidly severely sharp sharply swiftly swing whisk
ただちに (translations)→ direct immediate right
たちまち (translations)→ already completely hastily instantaneous momentarily short speedily
だしぬけに (translations)→ surprisingly unexpectedly
にわかに (translations)→ increasingly
はっと (translations)→ alarm alert automatically dead hurriedly jolt start startle
ぱっと (translations)→ excitedly fly
ぴたりと (translations)→ entirely full perfectly squarely still tight tightly
ふっと (translations)→ fleetingly passing softly unsummoned
ふと (translations)→ accidental chance dare inadvertently involuntarily momentary unbidden when
ぶっきらぼうに (translations)→ brusquely crisp curtly gruffly noncommittal sourly tersely
まっすぐ (translations)→ erect hard slap steadily straight upright
やおら (translations)→ before presently quietly slowly then till
わざと (translations)→ artfully consciously deliberate deliberately intentionally mock purposely rather self-consciously show thoughtfully treat willfully
ポツンと (translations)→ forlornly solitary
俄然 (translations)→ really rush
急な (translations)→ emergency steepish
急に (translations)→ begin considerably snap
急激に (translations)→ dramatically exponentially significantly
早速 (translations)→ promptness
唐突に (translations)→ inconsequently surprised
同時に (translations)→ along also at but concurrently incidentally simultaneous together while
突然 (translations)→ easily levity until
不意に (translations)→ unscheduled
乱暴に (translations)→ crossly fitfully furiously giddy harshly impatient madly radical roughly rudely savagely viciously