Furuhashi Sakurakyu had lied to Kimura Kazuki before.
When Kimura Kazuki asked her what her obsession was, she lied because she had to take care of her four daughters. She hoped that Kimura Kazuki could take good care of her daughters, and fulfill their life goals. Of course, according to Furuhashi Sakurakyu's thoughts, she had hoped that Kimura Kazuki could take care of them for their entire lives.
This was a very selfish thought, but Furuhashi Sakurakyu turned out to not be so impertinent in the end. Of course, if she really was that impertinent, Kimura Kazuki would have let her die through euthanasia.
As dawn approached, Kimura Kazuki remained silent when Furuhashi Sakurakyu stated the problem with a worried look. He had not expected Furuhashi Sakurakyu to lie about her obsession. He should have noticed it earlier, because Furuhashi Sakurakyu seemed to always be in a state of anxiety, and he was confused by that.