He's not sure of what he's seeing in absolutely any context. His vision is distorted, too colourful, and Himeka herself feels hard to hold onto, like well-arranged sparkles rather than a human form. It just makes him hold onto her tail more determinedly.

"I'd rather... you stay here."

He's too anxious about this to fly, he thinks. He feels like if he flies right now he isn't going to come back down. It's a level of emotional freedom that he isn't prepared to indulge in. If she just disappears, what is he even going to do about it?