- Dear Tohsaka, written from Sakura's perspective,
- Dear Emiya, written from Shinji's perspective, and
- Dear Matou, written from Rin's perspective.
This series follows the aftermath events of the True End of the Unlimited Blade Works route. Sakura writes a letter to Rin, detailing her life and feelings. The sequels take place not long after the first story. Shinji writes a letter from his point of view; and finally the last letter is about Rin, who concludes the events. Each fic is one chapter long, but they are incredibly emotional.
- Bittersweet Ending: The Letter Series ends with Shirou and Rin holding hands as they finish visiting Sakura's grave.
- Also debatably and to a lesser extent, Shinji.
- Death by Adaptation: Sakura commits suicide by drinking a special poison, thus killing Zouken as well, since he is connected to Sakura by the worms. Six years later, Shinji dies because his body started deteriorating as a secondary effect of being exposed to the tainted Holy Grail.
- Emotionless Girl: Sakura becomes this eventually, with some intervention from Kohaku.
- I Just Want to Be You: In Dear Tohsaka, Sakura openly admits that she wanted to be like Rin because she had Shirou's love and because to her she was everything she could have been if she hasn't been adopted by the Matou family.Sakura: "What would it be like if I was truly your sister, these were the things I dreamed about, smiling into my pillow, people would call me Sakura Tohsaka and they would say I was the number two idol of the school, I'm sure of it, I know I would never beat you. We would break every heart in the school, twice! Go to the same classes, chase the same boys, and cook the most amazing food together. And at night, maybe, we would sleep together in the same bed, like I hear a lot of sisters do, the worst fear we could ever imagine is to be separated from each other, even for a day. And I would call you Nee-san."
- Also, in Dear Emiya, Shinji declares that he never loved Rin, but she was everything he ever wanted to be.
- I Want My Beloved to Be Happy: Sakura to Shirou, despite the fact that he ended up with her sister Rin.
- Karmic Death: Shinji is dealt a slow and painful death, regretting what he had done in his life. thus mirroring Kiritsugu's fate (because in Shinji's letter, he comments that he had a similar fate as he was infected by the tainted Grail and abandoned his ideals).
- Never Got to Say Goodbye: After Sakura's suicide, Rin, Shinji and Shirou feel this in varying degrees.
- Not So Different: Kohaku, from Tsukihime, points this to Sakura in the middle of her Despair Event Horizon
- Meaningful Rename: In Dear Emiya, Shinji changes his surname from Matou to Emiya, after realizing the terrible things his family did, thus changing his ideals.
- My God, What Have I Done?
- Parting Words Regret: Shinji has a painful death and laments that Sakura committed suicide when he couldn't apologize for all the crap he put on her all those years.
- Also Sakura's only regret when dying is that she never could have called Rin by the suffix "Nee-san". In Dear Matou, Rin replies that she would have loved to.