Writing Japanese on Windows

MS Windows serves IME(Input Method Editor) to write Japanese characters.
Here is a useful link for your information.

Writing Japanese on the Windows Platform

There are two main input methods, one is 'Romaji (means Roman letters in Japanese) input', another is 'Kana (means Japanese letters in Japanese) input'. To use 'Kana input', you have to memorize the layout of Japanese standard keyboard, and it takes a lot of time for you to be familiar with. 'Romaji input' is usually better choice for non-Japanese. (even for Japanese) 'Romaji' is the romanized version of Japanese letters, which have one-to-one matching to original ones. See the following table.

日本語ひらがなローマ字入力表
Japanese Romaji Input Table
MS-IME
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ぁ = la うぇ = whe ぎ = gi くぉ = qo
ぁ = xa うぉ = who ぎぃ = gyi くぉ = qwo
あ = a ぇ = le ぎぇ = gye くゃ = qya
ぃ = li ぇ = lye ぎゃ = gya くゅ = qyu
ぃ = lyi ぇ = xe ぎゅ = gyu くょ = qyo
ぃ = xi ぇ = xye ぎょ = gyo ぐ = gu
ぃ = xyi え = e く = cu ぐぁ = gwa
い = i ぉ = lo く = ku ぐぃ = gwi
い = yi ぉ = xo く = qu ぐぅ = gwu
いぇ = ye お = o くぁ = kwa ぐぇ = gwe
ぅ = lu か = ca くぁ = qa ぐぉ = gwo
ぅ = xu か = ka くぁ = qwa け = ke
う = u が = ga くぃ = qi げ = ge
う = whu き = ki くぃ = qwi こ = co
う = wu きぃ = kyi くぃ = qyi こ = ko
うぁ = wha きぇ = kye くぅ = qwu ご = go
うぃ = whi きゃ = kya くぇ = qe さ = sa
うぃ = wi きゅ = kyu くぇ = qwe ざ = za
うぇ = we きょ = kyo くぇ = qye し = ci
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し = shi じゃ = jya ぞ = zo ぢ = di
し = si じゃ = zya た = ta ぢぃ = dyi
しぃ = syi じゅ = ju だ = da ぢぇ = dye
しぇ = she じゅ = jyu ち = chi ぢゃ = dya
しぇ = sye じゅ = zyu ち = ti ぢゅ = dyu
しゃ = sha じょ = jo ちぃ = cyi ぢょ = dyo
しゃ = sya じょ = jyo ちぃ = tyi っ = ltsu
しゅ = shu じょ = zyo ちぇ = che っ = ltu
しゅ = syu す = su ちぇ = cye っ = xtu
しょ = sho すぁ = swa ちぇ = tye つ = tsu
しょ = syo すぃ = swi ちゃ = cha つ = tu
じ = ji すぅ = swu ちゃ = cya つぁ = tsa
じ = zi すぇ = swe ちゃ = tya つぃ = tsi
じぃ = jyi すぉ = swo ちゅ = chu つぇ = tse
じぃ = zyi ず = zu ちゅ = cyu つぉ = tso
じぇ = je せ = ce ちゅ = tyu づ = du
じぇ = jye せ = se ちょ = cho て = te
じぇ = zye ぜ = ze ちょ = cyo てぃ = thi
じゃ = ja そ = so ちょ = tyo てぇ = the
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てゃ = tha どぇ = dwe ひゅ = hyu ふぃ = fwi
てゅ = thu どぉ = dwo ひょ = hyo ふぃ = fyi
てょ = tho な = na び = bi ふぅ = fwu
で = de に = ni びぃ = byi ふぇ = fe
でぃ = dhi にぃ = nyi びぇ = bye ふぇ = fwe
でぇ = dhe にぇ = nye びゃ = bya ふぇ = fye
でゃ = dha にゃ = nya びゅ = byu ふぉ = fo
でゅ = dhu にゅ = nyu びょ = byo ふぉ = fwo
でょ = dho にょ = nyo ぴ = pi ふゃ = fya
と = to ぬ = nu ぴぃ = pyi ふゅ = fyu
とぁ = twa ね = ne ぴぇ = pye ふょ = fyo
とぃ = twi の = no ぴゃ = pya ぶ = bu
とぅ = twu は = ha ぴゅ = pyu ぷ = pu
とぇ = twe ば = ba ぴょ = pyo へ = he
とぉ = two ぱ = pa ふ = fu べ = be
ど = do ひ = hi ふ = hu ぺ = pe
どぁ = dwa ひぃ = hyi ふぁ = fa ほ = ho
どぃ = dwi ひぇ = hye ふぁ = fwa ぼ = bo
どぅ = dwu ひゃ = hya ふぃ = fi ぽ = po
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ま = ma ら = ra ヴぃ = vyi
み = mi り = ri ヴぇ = ve
みぃ = myi りぃ = ryi ヴぇ = vye
みぇ = mye りぇ = rye ヴぉ = vo
みゃ = mya りゃ = rya ヴゃ = vya
みゅ = myu りゅ = ryu ヴゅ = vyu
みょ = myo りょ = ryo ヴょ = vyo
む = mu る = ru ヵ = lka
め = me れ = re ヵ = xka
も = mo ろ = ro ヶ = lke
ゃ = lya ゎ = lwa ヶ = xke
ゃ = xya ゎ = xwa
や = ya わ = wa
ゅ = lyu を = wo
ゅ = xyu ん = nn
ゆ = yu ん = xn
ょ = lyo ヴ = vu
ょ = xyo ヴぁ = va
よ = yo ヴぃ = vi
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For example, to write 'はじめまして (means 'nice to meet you')’, you just need to type 'hajimemasite'. Easy.