The Oneechan Bara

All bonuses:
Quickly press Up, Down, Up, Down, L1, R1, L2, R2, L3, R3, Up, Down, Up, Down, L1, R1, L2, R2, L3, R3 when "Push Start Button" appears at the title screen. A sound will confirm correct code entry. Enter quest mode to unlock all secrets.
Dani.

Hard difficulty:
Successfully complete stage 6 under the normal difficulty setting in story mode.
Dani.

Violent difficulty:
Successfully complete stage 6 under the hard difficulty setting in story mode.
Dani.

Wallpaper 2:
Successfully complete 2 quest mode missions in story mode. Press L1, L2, R1, or R2 at the mode selection screen to cycle through the wallpaper.
Dani.

Wallpaper 3:
Successfully complete 4 quest mode missions in story mode. Press L1, L2, R1, or R2 at the mode selection screen to cycle through the wallpaper.
Dani.

Costume 2:
Successfully complete 6 quest mode missions in story mode.
Dani.

Costume 3:
Successfully complete 8 quest mode missions in story mode.
Dani.

Costume 4:
Successfully complete 10 quest mode missions in story mode.
Dani.

Costume 5:
Completely fill the ???? meter.
Dani.

Costume 6:
Successfully complete stage 6 under the violent difficulty setting in story mode.
Dani.