Summer, The Sea, Youth! And A Ghost As Well
The Summer, the Beach, Youth and Ghosts
Natsu yo Umi yo Seishun yo! Omake ni yurei mo yo!
"It's summertime, and the girls search for a vacation spot so they can get away and focus on training. Instead of finding a beautiful beach destination, they settle on an ominous-looking mansion that has a very eerie service staff." (source)