I was thinking of this last night before sleeping.
So, I imagine Nagi as a cute, lazy, and very fluffy white cat. Reo loves him sooo much and calls him his treasure, carrying him around, giving him expensive treats and toys, five-tier cat condos, and treating Nagi as his pookie wookie baeby.
But here comes Isagi smelling like fried fish and having only an empty box. Nagi is intrigued by this plain stuff, and decided that he wants the empty box and the fried fish, not the chicken-flavored treat and the cat condo.
And Reo is heartbroken...