Taiyo Asano has been on his own ever since his parents died. The only one who seems to care for him is his childhood friend and classmate, Mutsumi Yozakura. But Mutsumi has a secret--she is the head of a family of spies!

Taiyo somehow manages to survive the Silver-Rank spy exam, earning his promotion. He finally gets to talk to Kawashita and relay Tsubomi's desire to perish. He quickly learns that Kawashita also faces an unenviable fate. To make matters worse, Momo Yozakura appears!