nkfコマンドを使います。
$ brew install nkf

ふつうにwhoisすると

log

$ whois -h whois.nic.ad.jp 182.22.59.229
[ JPNIC database provides information regarding IP address and ASN. Its use   ]
[ is restricted to network administration purposes. For further information,  ]
[ use 'whois -h whois.nic.ad.jp help'. To only display English output,        ]
[ add '/e' at the end of command, e.g. 'whois -h whois.nic.ad.jp xxx/e'.      ]

Network Information: [B%M%C%H%o!<%/>pJs]
a. [IPB%M%C%H%o!<%/%"%I%l%9]     182.22.0.0/17
b. [B%M%C%H%o!<%/L>]             YAHOO-NET
f. [BAH?%L>]                     B%d%U!<3t<02q<R
g. [Organization]               Yahoo Japan Corporation
m. [B4IM}<TO"MmAk8}]             JP00032461
n. [B5;=QO"MmC4Ev<T]             JP00032461
p. [B%M!<%`%5!<%P]               ns01.yahoo.co.jp
p. [B%M!<%`%5!<%P]               ns02.yahoo.co.jp
p. [B%M!<%`%5!<%P]               ns11.yahoo.co.jp
p. [B%M!<%`%5!<%P]               ns12.yahoo.co.jp
[B3dEvG/7nF|]                    2010/06/03
[BJV5QG/7nF|]
[B:G=*99?7]                      2011/09/26 15:59:02(JST)

B>e0L>pJs
----------
B%d%U!<3t<02q<R (Yahoo Japan Corporation)
                     [B3d$j?6$j]                                  182.22.0.0/17

B2<0L>pJs
----------
B3:Ev$9$k%G!<%?$,$"$j$^$;$s!#

nkfコマンドを使うと

log

$ whois -h whois.nic.ad.jp 182.22.59.229 | nkf -w
[ JPNIC database provides information regarding IP address and ASN. Its use   ]
[ is restricted to network administration purposes. For further information,  ]
[ use 'whois -h whois.nic.ad.jp help'. To only display English output,        ]
[ add '/e' at the end of command, e.g. 'whois -h whois.nic.ad.jp xxx/e'.      ]

Network Information: [ネットワーク情報]
a. [IPネットワークアドレス]     182.22.0.0/17
b. [ネットワーク名]             YAHOO-NET
f. [組織名]                     ヤフー株式会社
g. [Organization]               Yahoo Japan Corporation
m. [管理者連絡窓口]             JP00032461
n. [技術連絡担当者]             JP00032461
p. [ネームサーバ]               ns01.yahoo.co.jp
p. [ネームサーバ]               ns02.yahoo.co.jp
p. [ネームサーバ]               ns11.yahoo.co.jp
p. [ネームサーバ]               ns12.yahoo.co.jp
[割当年月日]                    2010/06/03
[返却年月日]
[最終更新]                      2011/09/26 15:59:02(JST)

上位情報
----------
ヤフー株式会社 (Yahoo Japan Corporation)
                     [割り振り]                                  182.22.0.0/17

下位情報
----------
該当するデータがありません。