With Hayato asleep, Ryuutaro had a hard time staying awake himself. The panic that had come over him when Hayato was shot and he saw him in the middle of all this blood was slowly wearing off. Hayato was here, alive, next to him. Something like... back then... wasn't going to happen again.
He wouldn't let it happen. Even if he had no idea how to actually prevent it.

For now that wasn't important. It was merely important that whatever Ryuutaro did, Hayato wouldn't disappear just right away. If he closed his eyes, the other would be there when he opened them again. He wasn't 100 percent sure, but being both exhausted from a sleepless night and the mental trouble itself, it didn't actually matter anymore.

By the time they reached their destination he was asleep as well, only half-way waking up when Bianchi opened the door.