historian

(Internet slang, especially anime and manga fandom) events or things from the past which one wants to whitewash/erase from history (due to it being embarrassing, poorly received, etc.); dark past

study of history

historic, historical / already-happened, past / former, old, traditional

Kyūjitai form of 戦闘 (“battle; combat; fight”)

Kyūjitai form of 海戦 (“naval battle”)

war record, military achievements

victory, triumph

Kyūjitai form of 戦争 (“war”)

Kyūjitai form of 戦役 (“war; battle”)