Saya infiltrates a girls' boarding school, the Lycee des Cinq Fleches. Hagi too sneaks in, disguised a gardener. Saya learns from her roommate Ming about a legend of a phantom who fell in love with the prettiest girl from the school and who presented her with a blue rose flower.

In Hanoi, Kai and Riku encounter a beautiful girl, Mui, who lost her left leg to an unexploded bomb that had detonated. In the meantime, David and his group analyze the photos of the past phantom incidents at the lycee and find out that the past victims all had black hair and Oriental complexions. They realized Saya was lured out deliberately. Meanwhile, in Naha, Okinawa, Okamura prepares to go to Vietnam on a paid holiday. Then, from the belongings left by his late photographer father, who covered the battlefields, Okamura finds a photo...

In the morning, as Saya comes into her classroom, she finds a blue rose.

Students are murmuring about the phantom legend that has been the gossip at the lycee. Saya and Hagi sneak into a rose garden beside the church where it is said the blue roses were in bloom. And they find steps leading to the underground...

An annual ball is being held in the lycee. Students, guardians and guests in formal attire are gathered in the school cafeteria when Saya arrives in a dress she borrowed from Min. On the dance floor, Saya meets a young man named Solomon, who asks her for a dance. As the music starts, David reaches the entrance to the basement surrounded by blue roses...