猫(ねこ)に小判(こばん)
Cast Pearls to a Swine

• Japanese: ねこ に こばん neko ni koban
• Literal: Give money to a cat
• English Equivalent: To cast pearls before swine
• Notes: 猫に neko ni (give) to a cat [に shows direction]; A 小判 koban was an oval gold coin used during the Edo period; 豚に真珠 buta ni shinju Pearls to a pig, from the Bible, is also used often and means basically the same thing.

宝石(ほうせき)に興味(きょうみ)のない人(ひと)にダイヤモンドをあげても、猫(ねこ)に小判(こばん)だ。
houseki ni kyoumi no nai hito ni daiyamondo o agetemo, neko ni koban da.
For someone who has no interest in precious stones, even giving him a diamond would be casting pearls before swine.

宝石 houseki—precious stones, gems
興味のない人 kyoumi no nai hito—a person not interested in…
ダイヤモンド daiyamondo—diamond
あげても agete mo—even if (you give him a diamond)