How do I write the equivalent ofトー (tō) in hiragana?

Question

I am trying to write a character's name, given to me in katakana, in hiragana. The character's name ends in "トー" (tō). I'm brand new to Japanese and learned that ー is the "chōonpu," which signifies a long vowel in katakana. Wikipedia gives a table for the equivalent in hiragana with the "h" sound, and says that "ホー" (hō) is "ほお or ほう." So then, using the "t" sound, I would have "とお or とう", right?

My question is, what is the difference between the two? And which one should I use? The appropriate sound for the name would be like the English word "toe."

Answer 1

First, can I assume this name is from some non-Japanese culture? The basic rule is that foreign (western) names should normally be written in katakana, and you have a good reason to use hiragana. When you do have a good reason to "hiraganize" a word that is normally written in katakana, it's fine to use the chōonpu with hiragana. In your case, とー is probably the way to go. (One valid reason is this, although I don't recommend this to a beginner.)

For historical reasons, とお and とう are both used for the same /tō/ sound depending on the word, but these spellings are for traditional Japanese words such as とうさん (tōsan, "father") and とおり (tōri, "street"). You don't have to respect this rule for foreign words that are hiraganized for some good reason.