SCP (Animation Game System)
While this may not apply to all games that use this engine, the scripts text can be modified. Japanese text is encoded in shift_JIS but will accept ANSI (single byte/half width?) without issue. Not sure if there is any word wrapping used but scripts can always be fixed to give the appears of it. If opcode found for end line or next line is found, makes it even easier so there is no delay on text appearing due to use to white space to pad line till end of line.