報い, 酬い: (positive) reward, recompense, or (negative) retribution for having done something / 報い, 酬い: karma, karmic effect from something done in a previous life

マテガイ: a razor clam, more specifically Gould's razor shell: Solen strictus.

leadership

the guard at the end of the grip of a sword or polearm / the brim or visor (of a hat, for example) / the brim of a kettle