Rune Factory 4's love system works like this. First, you woo the girl. Then, you give the girl presents, building your relationship further. Then, you confess your love.

Then...

...

Maybe...

...

Just maybe

...

You'll get to see the girl in her pajamas!

The game also has the more traditional swimsuits, Famitsu.com confirms.

In addition to these forbidden pajama screens, Famitsu.com provided a look at your latest beast lover. As previously reported, in Rune Factory 4, some boss monsters turn into human form once defeated and can be the targets for your wooing. Today's boss monster turned lover is Leon.

Use the proper techniques, and perhaps you'll get to see Leon in his pjs at some point.