Actually you can do some fancy things by using stopwatch in Japanese versions. If you bring a stopwatch and defeat Dracula, use a stopwatch just before grabbing the ball and beat the game, the staff roll would show a different color (the color scheme of things being affected by stopwatch in-game).
And a music playback issue could happen when you use a stopwatch during the time a boss has been defeated. The stage clear music will sometimes come out before grabbing the boss's ball. I'm not sure if it's really THE infamous music issue exist in the Japanese version, but Japanese PSN version (launched February 12, 2014 in JP region) does have problems related to stopwatch.
The accursed evil IGA! One thing, the man named Matsufuji is always in the staff member of GBA and DS handheld Castlevania games related to IGA. His name is only exist in the JP versions.