せ, in hiragana, or セ in katakana, is one of the Japanese kana, each of which represents one mora. Both represent the sound, and when written with dakuten represent the sound [ze]. In the Ainu language, the katakana セ is sometimes written with a handakuten (which can be entered into a computer as either one character or two combined ones to represent the sound, and is interchangeable with ツェ.