Battle Raper II

Bonus costumes and costume accessories:
Finish the game at least once, then go to Free Mode battle and consistently
win against a CPU opponent. Every 10 wins wear your own girl doesn't get her
clothes destroyed will award you an extra costume.

Unlock Hentai-Mode Replay:
Finish Story Mode with a selected girl. Note: this includes completing the sex
scene with the selected girl until the credits are issued (do not quit to title
or exit the game). To access the H-replays, go to Replay, then the Extras menu
are auto-saved to your profile when the credits are displayed.

Unlock CG Images in the Extras menu:
Complete Story Mode with all the girls.

Note that the stage you select after fighting the first enemy determines which
set of girls you unlock (that time).

To unlock Setsuna Yagami's CG (the ninja girl), you need to select the bottom
option after playing either set of girls the first time (it is the first
decision in Story Mode).

The other girls are "unlocked" when you select them in the second decision
window.