<i>Koiguchi</i> the mouth of the scabbard <i>saya</i> of a Japanese sword.  The blade of a sword is returned to the <i>saya</i> through the <i>koiguchi</i>.
<a href="//commons.wikimedia.org/wiki/User:Samuraiantiqueworld" class="mw-redirect" title="User:Samuraiantiqueworld">Samuraiantiqueworld</a>
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<span class="int-own-work" lang="en">Own work</span>