- "Time Machine" from F is positively heartbreaking, as are extend's "Starduster" and "Kokoro/Heart" from 2nd and F 2nd.
- In "Time Machine", after a summer of assorted carefree activities, the POV character gets on a train and leaves the helplessly crying performer behind.
- In "Starduster", Miku's astronaut fiancée perishes on a space mission, but the two are reunited in death an unspecified amount of time later.
- And the relentlessly cheery "Kokoro" is about Rin, a robot, who gains a heart by some miracle. Sadly, her frail machine body couldn't contain her heart, so she eventually dies. The ending text scroll informs us that she died with a smile on her face, and that she looked like an angel.
- The Mirai DX version is even worse despite the chibi art style: She sprouts angel wings and flies towards the heavens to meet her creator, who waits for her with open arms, but her wings fall apart and she, along with Futile Hand Reach, mouths a final "Thank you," to him before shedding a single tear and shutting down.
- Sakura Rain is the only song in the Project Diva F sub-series to even visit the school that appeared prominently in the intros of the Project Diva games on the PSP. It's strongly implied that no-one attends the school any more, and Miku is likely taking some camera phone footage of it before it's closed for good.
- Even worse, The minimal storyline of Project Diva X implies that most, if not all, of the Vocaloids' world has disappeared into a void. Miku's school may well not even exist as a ruin.
- Soundless Voice in F 2nd, where Len laments the death of Rin. Poor Len.... It gets worse if you just did the song Suki Kirai.
- "Hello Planet" sounds like a cheerful and optimistic song... until you hear the words, and realize that Miku is in a post-apocalyptic world, and her quest is doomed to fail. Soundtrack Dissonance at it's most heartbreaking.
- The story of "Knife" with Len killing Miku and Rin immediately getting revenge. Ends with a We Used to Be Friends shot of the trio in the moon.
- The story of "Aku no Musume," which makes us to believe that the evil Princess Riliane (Rin) is executed, only to find out via "Aku no Meshitsukai" that her twin brother Allen (Len) took her place instead.
- Hiroshi Utsumi's departure, and the subsequent abrupt sunsetting of the entire franchise... as everyone was celebrating the coming of Miku's 10th anniversary.
Tear Jerker / Hatsune Miku: Project DIVA