To what famous work is the story "Samsa in Love" alluding throughout its narrative and how do you know?

In the very first sentence of the story "Samsa in Love," the reader learns that the protagonist has just awakened to find that he has experienced a "metamorphosis" (186) and is now Gregor Samsa. It is clear, then, that Murakami expects his reading audience to be familiar with Franz Kafka's famous novella entitled The Metamorphosis, which revolves around one Gregor Samsa.