Dual protagonists, male and female protagonists are not CP
Introduction to male version:
I thought I could swim into my brother's heart, but I didn't expect to swim into my brother's fish pond. In the end, I found out that my brother didn't fish at all, and all the fish were voluntary.
Female protagonist version introduction:
I thought my sister was a winner in life, but I didn't expect that my sister was an extraordinary wage earner who could never defeat the boss.
But she has me, and I sell fish to support her.