彼岸 translates the Sanskrit pāramitā — the 'far shore' of enlightenment, opposite
此岸 (cǐ'àn, 'this shore' — the world of suffering). The metaphor of a river crossing is central to Mahayana Buddhism and runs through East Asian poetry. The red spider lily is called
彼岸花 (bǐ'ànhuā) because it blooms around the autumn equinox
彼岸 festival in Japan.