It had been a while since a mysterious disease was discovered in modern times. TS disease is a condition that only affects males and turns them into females in an instant once it manifests. My best friend, with whom I had always been close, unfortunately, contracted this TS disease. Changing from male to female, naturally, many things began to change. But I couldn’t abandon him… no, her. Even if her appearance changed and she became a woman, she was still my precious best friend. That was something I believed would never change, no matter what happened.