Timeline (follows anime): After Ranma finds out Akane's crush on Dr. Tofu (and he tells her Akane the possibility of her and Dr. Tofu getting together could still happen), before Ryoga accidentally cuts Akane's hair.
Ranma had meant it when he said a relationship between Akane and Dr. Tofu could happen. He didn't just say it in hopes of cheering her up. Dr. Tofu, Ranma could easily admit, was a really good guy.
Ranma looked up from his schoolwork and turned his direction to his fiancée.
Akane, when she didn't have to deal with him and therefore when she kept her temper, was probably the nicest and sweetest girl he knew. She had a cute smile that was never directed towards him; the blush on her cheek was meant for someone else. And that's why he could see it happening. Dr. Tofu brought out the best in Akane, a talent that Ranma could not boast for himself.
He stared at Akane for a few moments. Her chin rested on a propped hand, and he idly wondered what she was thinking about. She tucked a strand of her impossibly long hair behind her ear. And, as if she could feel his gaze on her, she turned her head back. Their eyes met, but Ranma was the first to look away.
Ranma couldn't understand why, but he really hoped nothing would happen between the chiropractor and his fiancée.