It’s a bit more complicated: if you’re dealing with the sounds it’s transcription, if you’re converting from writing system into another it’s transliteration.
So for example, what you did is transliteration. But if you were to record some Japanese guy speaking and wrote it down (in kanji+kana, Latin, or even IPA), or if you handled how it’s actually spoken, it would be transcription.
It’s a bit more complicated: if you’re dealing with the sounds it’s transcription, if you’re converting from writing system into another it’s transliteration.
So for example, what you did is transliteration. But if you were to record some Japanese guy speaking and wrote it down (in kanji+kana, Latin, or even IPA), or if you handled how it’s actually spoken, it would be transcription.