Nana, a female student who attends a young lady's school, is in love with Yoshida, a college student. Nana, who grew up in a father-son family, began dating Yoshida, who was a part-time worker who had only done it once, because her father was busy with work and lived semi-alone. Yoshida was like a boyfriend, brother, and father to Nana. Only a bright future awaited them. One day, Saji, a half-gray man who is burdened with debt to Yoshida, appears and sets his eyes on Nana. It ...... be a gateway to hell for both of them.