In the manga version of Chrono Crusade, after a traumatic battle Chrono is practically catatonic with grief. After diving into his mind to learn of his (tragic) past, Rosette confronts Chrono when she finds him in a dark corner of his mind about how he's running away. When Chrono admits he's doing it to protect her (as his powers drain her life away due to their contract), Rosette yells at him, telling him he can't make a decision like that for her. However, diving can drain on spiritual energy, which causes both the shadowy representation of Rosette in Chrono's mind and the real physical body of Rosette to collapse...and at that moment, Chrono breaks out of his near-coma as he dives to catch her from falling. The scene ends with Rosette asking Chrono to allow them to deal with each other's pain together.. Probably one of the most tear-jerking scenes in the manga, but in a good way.
Also from the manga, volume 7: As Aion's final plan is being put into motion, Fiore tells Joshua that she's leaving to join the battle when he stops her—making a (correct) guess that Aion actually ordered her to stay with Joshua and kill him as soon as the horns on his head poison his mind and take away what's left of his sanity, saying that "it's written all over your face". This leads to the following exchange:
Joshua: Yeah, I know...[hugging her from behind] But it's written on your face.
Fiore then asks Joshua to call her "sister" one last time, and leaves. It's the last time they ever see each other.
Joshua finally tearing off Chrono's attached horn, realizes his promise to Rosette to grow strong and be adults together, and realizes that he can't fulfill his promises by keep depending on Chrono's horn (which also caused Chrono so much limitation in the beginning).
In the manga, after Rosette had died, she was riding a train, with vague memories of what happened to her. She mused to herself that she's satisfied and she's done everything she could. However, a cloaked figure sitting across from her asked her was she truly satisfied? Rosette began to argue with the stranger that she endured so much, always running. Then, the stranger calmly pointed out if she was truly satisfied, why was she looking out the window all this time? Who was she looking for? An image of Chrono flashed before her and Rosette finally remembered everything. She ran to the end of the train, sobbing as she said she didn't want to leave Chrono. The stranger asked her does she still want to keep running? And her reply was jumping off the train and returning back into the real world.
Then, we find out that the cloaked figure was Mary Magdalene, whose spirit was always with them.
Mary: "Let's go. We can go back together ... back to the person we care about."
To stop Aion, both Rosette and Chrono volunteer to go. However, Chrono froze Rosette in her tracks since he now has his horns back, telling her that this was a one-way trip and he will stop Aion on his own. Right before he leaves, he embraces Rosette gently and kissed her for the first and last time.
In the epilogue of the manga, (here◊ ya go), many years after the battle with Aion, Rosette is sitting alone in a church when suddenly, she suffered a seizure. Her doctor warned her that this one might be the one that would end her life. Crying out in pain, she called out for Joshua, Azmaria and ... Chrono. However, Chrono hasn't been seen in years as well. Thinking she might die alone, Rosette continually called for Chrono. Then, the church door opened, revealing a bright light and one lone figure. The rest of the panels are shown without words or sounds, but it was pretty clear. Chrono finally returned and she managed to stand up and run towards him, jumping into his arms, with a jubilant smile on her face.
"The place Chrono could go back to was decided four years ago!" by Rosette to demons that wanted Chrono back to their side. Just to name one.