Kazuna satisfies his craving by drinking Chizuna's blood. Chizuna welcomes it and wants to merge with his flesh and blood. Kazuna, however, feels inadequate; he wants to be for Chizuna what she is to him. But Chizuna refuses to drink Kazuna's blood because that would associate him with her father. Minase withholds any further medication from Chizuna, fearing its dangerous effects on her. He tells Kazuna to exercise some influence on her and help control her symptoms. Minase, meanwhile, reflects on his long-standing and unshakeable attachment to Chizuna and his knowledge that she will never accept him as one of her own. Just then, he notices Yaegashi at the clinic inquiring about Kazuna's address. He tells her that Kazuna's moved in with her ailing sister, far away, and that she should stop looking for him Yaegashi reveals to Minase that she knows that Kazuna suffers from the same illness. Minase tells her to stay away from him, that it would only prolong her misery if she continued her efforts to find Kazuna. Nevertheless, out of love and loyalty, Yaegashi says she will persist. Minase relents and gives her Kazuna's address.
Chizuna, having stopped her dosage of the powerful medicine, is anxious about what will happen should her symptoms arise again. Just then, Aunt Natsuko shows up with a proposition for them. She and Uncle Eda want to adopt both of them. She tells them that they can still stay together in their family home and, together, they'll fight their illness. Chizuna rejects her proposition. She says that she cannot bring anyone outside the Takeshiro family into the fold of this horrible illness. Her fate is sealed and to accept Aunt Natsuko's notions of a "happy little family" would be illusory and tragic. Kazuna agrees. Dejected, Aunt Natsuko leaves. Chizuna, still reeling from her medicine withdrawal, is stricken with fever and in the grip of a vampiric attack. Kazuna willingly offers his blood to her, but she refuses, not wanting to re-create with him the relationship she had with her father. Chizuna then collapses. Minase-san rushes in and whisks her off, accompanied by Kazuna, to recover at an old clinic once run by Chizuna's father. Minase leaves her there for observation and tells Kazuna he must keep away while she's ailing.
Later that day, Kazuna gets a shock when he's approached by Yaegashi. Again, Kazuna pleads with her to forget about him, that a life together would be terrible. Yaegashi, in turn, admits that the days since he went away have been unbearable for her. Kazuna runs off, but the thought of the possessive Chizuna keeps Yaegashi from following him. Back at the house, Kazuna contemplates the futility of his helping Chizuna. He feels overwhelmed by her illness and diminished by his powerlessness. Back at the clinic, Minase orders Chizuna never to return to her old house. The advanced state of her disease, combined with Kazuna's presence, could be fatally dangerous, he says. He insists that Chizuna make herself at home at the clinic. But, after he leaves, she attempts to escape and hitch a ride back to the family home in Tokyo. She passes out on the road and is brought back by a local. Minase is anxious about her declining health. But Chizuna tells him that her situation is hopeless: with or without treatment, she's going to weaken. Her days are numbered. All she wants now is to return to Tokyo.
Chizuna tells Minase that, no matter what, she will never drink Kazuna's blood and bind him to her fate, a fate that only she bears the burden of. By resisting Kazuna's blood, she is also freeing herself of the emotional grip exerted by her father. Minase refuses to give over the medicine, and he breaks down, expressing resentment that Kazuna took his place and regret because he wasn't the one to save Chizuna. Minase regrets that Chizuna never returned the passionate feelings that he's always had for her. Chizuna realizes that, for far too long, she's strung Minase's heart along, that he looks upon her that same way she obsessed over her father before he died. The next day, Minase finds that Chizuna is gone and that she's left a note. It's a parting note, expressing her lifelong gratitude to him and the inevitability of her decision to continue her deadly treatment if only to spend her last days with Kazuna. Minase despairs, but he does not regret his devotion to this woman.