on second thought; on further reflection
Used to introduce a reconsidered opinion or a contrasting viewpoint after thinking more deeply. Often appears at the beginning of a sentence.
See also: 翻って (ひるがえって)
On second thought, his proposal might be more realistic.
On further reflection, I should have been more careful at that time.
Standard kanji spelling for this set phrase.
Kana spelling is acceptable and may be easier for learners, though the kanji form is common.
Combination of the adverb 翻って (ひるがえって, 'on the contrary; conversely') and the conditional form of 考える (かんがえる, 'to think'). The adverb derives from the verb 翻る (ひるがえる, 'to turn over; to flutter'), suggesting a flipping or reversal of thought.