In the manga series Rurouni Kenshin, the character of Hajime Saito, who is based on the real historical figure, has a saying or motto, "Aku Soku Zan" (悪即斬), which is translated as "Slay evil immediately".
I found a few claims online that this was a real motto of the Shinsengumi the group that both historical Saito and fictional Saito are part of, but Wikipedia says it was probably not:
The "Aku Soku Zan" motto he lives by (悪即斬, most literally, "Kill those who are evil immediately,", translated as "Slay Evil Immediately" in the English dub and as "Swift Death to Evil" in the VIZ manga) is most likely fictitious, though it does encompass a common sentiment of the Shinsengumi during the Bakumatsu.
Is there any evidence that this phrase:
- Was a real Shinsengumi motto?
- Was a real motto of any contemporary group?
- Was a fictitious creation from literature or folk history that predated the manga series Rurouni Kenshin?