A story about me, who is fully prepared to lose, having a mysterious game of Othello with my hopeless childhood friend.

"Hehe. It looks like it's finally time for you to pay up!" That's Mizusaki Rio, my childhood friend, speaking with such confidence. She won the Othello tournament within the girls' tennis club and came to challenge me riding on that momentum. "There are two rules! First, we both give it our all, and second, the loser has to grant the winner one wish!" I thought as usual that she was being selfish, but I quietly psyched myself up. 'Alright, I'm going to lose.' Why am I planning to lose from the start? It's because I already know what her wish is.