Back before text messages when ポケベル (pokeberu) pagers were widely used, many Japanese people messaged each other using numbers.  The following is a short list of Japanese 1337 for you to use and enjoy:

• 0840 = おはよう = ohayou = hello
• 860 = ハロー = haroo = hello
• 10690 = テルくれ = teru kure = gimme yo’ numbah
• 18 = イヤ = iya = no/don’t wanna
• 3476 = さよなら = sayonara = bye
• 8181 = バイバイ = bai bai = bye bye
• 0833 = おやすみ= oyasumi = g’night
• 0833731 = おやすみなさい = oyasuminasai = good night/sweet dreams
• 8181 = はいはい = hai hai = okay/yeah
• 394 = 好きよ = suki yo = i like you/it
• 0139 = だいすき = daisuki = i really like you/it
• 14106 = 愛してる = aishiteru = i love you
• 724106 = 何してる = nani shiteru = what are you doing?
• 132 = ひみつ = himitsu = secret
• 09106=起きてる = okiteru = i’m awake
• 8110 = バイト = baito = part-time job
• 4510 = 仕事 = shigoto = work
• 3341 = 淋しい = samishii = i’m sad/lonely
• 111017 = 会いたいな = aitai na = i want to see you
• 38 171 = みんな いない = minna inai = nobody’s here
• 38 571 = みんな こない = minna konai = no one’s gonna come
• 5151 = 来い来い = koi koi = come come
• 88951 = 早く来い = hayaku koi = come quickly!
• 49 = 至急 = shikyuu = urgent/ASAP
• 02106 = 待ってる = matteru = i’m waiting
• 194 = 行くよ = iku yo = i’m leaving
• 114 = いいよ = ii yo = okay/that’s good
• 39 = サンキュー= sankyuu = thank you
• 3614 = 寒いよ = samui yo = it’s cold
• 4971 = 良くない = yokunai = that’s no good
• 0906 = 遅れる = okureru = i’m going to be late
• 504 = 困るよ = komaru yo = that troubles me
• 797 = 泣くな = naku na = don’t cry
• 2110 = ファイト！= faito! = fight! (do your best!)
• 889 = 早く = hayaku = quickly!
• 023 8462 881 = おっさん 走る の 早い = ossan hashiru no hayai = old man, you run fast!
• 00 893 4 = 俺ヤクザよ = ore yakuza yo = I’m yakuza
• 72?! = 何？！ = nani = what?!
• 061 = 悪い = warui = bad/no
• 2932 = 複雑 = fukuzatsu = it’s complicated
• 4444 = 良し良し = yoshi yoshi = good/good for you/there there
• 1414 = いよいよ = iyo iyo = at last
• 50 01417 = これ おいしいね = kore oishii ne = this is delicious, isn’t it?
• 558 20104 1059 = ここは 褌 天国 = koko wa fundoshi tengoku = this is loincloth heaven
• 00 10 046 3810647 = 俺 今 おしり 見えてる よね = ore ima oshiri mieteru yo ne = you can see my butt right now can’t you?
• 81 = はい = hai = yes