On the bus-ride home, Lucy again asks Kouta if she can go to the festival with him, but he has promised Yuka he would go with her. She jealously wonders if his cousin is a boy or a girl, while her inner voice tells her to kill him before he can hurt her. In an argument and struggle with the voice, Lucy snaps out of her thoughts to find she's been strangling Kouta.
She begins to fear for her sanity and begs Kouta to make a promise to kill her if she should ever become openly murderous. At the final stop, Lucy directly asks Kouta about his cousin's gender. Sensing her hurt feelings, Kouta decides to lie and say his cousin is a boy instead of s girl, though he worries that lie won't hold up if she keeps her promise to see him off at the train station the next night. Reassured, she writes a letter that she seals in a glass jar along with the jade stone and buries it next to her puppy's grave, asking his spirit to protect it.
Ch35p158
The breaking point of tragedy.
On the beachfront the next day, Kanae shows her brother and Yuka some shells she collected, only to have her efforts dismissed by Kouta, who she kicks in a rage. Yuka realizes that this is her last day together with Kouta and asks him if there is anything he would like to say to her. When he openly wonders what she might mean, she flies into a fit of rage and beans him with a seashell when he tries to leave. She just as quickly becomes concerned as she stands over his unconscious form and urges him to wake up. He surprises her by only feigning unconsciousness, but avoids her wrath when she is relieved to see he is alright. Kanae returns, covered in dirt from seeking out a shell to impress her brother, who gives her his praise. The family then departs for the festival.
At the festival, Kouta beats Yuka at a carving game, and she emotionally falls apart at the thought of him leaving. Embracing him, she begs him not to leave, embarrassing him and worrying him that his friend might end up seeing this. Calming Yuka down, his worst fears are realized as, just outside his sight, Lucy, who has vowed to confess her feelings of love for him, sees Yuka embracing Kouta and begins to fall apart.