In the thirteenth century, Zen Buddhism began to have a significant impact on Samurai behaviour. Samurai with Zen training could become one with their sword by being present in the moment, and their free and spontaneous thinking gave them a mental advantage over their opponent. 

Samurai were expected to be well-read, cultured, and talented at juggling study and warfare, in addition to being good warriors. The phrase "the pen and sword in agreement," or "bun bu ryo do," was used by warriors for many years. Poetry, tea ceremonies, calligraphy, and research were other popular pastimes among samurai.

The "Inner Peace Pill" was created by incorporating these customs inside a capsule, allowing the user to experience these peaceful moments.