Warning! Spoilers will be unmarked for the story! Proceed at your own peril.
Given how dark P5 and Death Note were, it was only natural that the story would have some scenes worthy of tears.
- Sayu's reaction to finding out that Light is Kira. She finds out because she overheard him during his Villainous Breakdown after L revealed he killed a stand-in. Try to picture what she's feeling right now: you have this awesome big brother who's perfect in every way...and then you find out he's a psychopath who thinks he's god and will kill anyone who disagrees with him. Somebody give this girl a hug.
- It's a minor note, but it hurts all the same. Especially to the Yagami family. In this continuinty, Sachiko Yagami, Light and Sayu's mother, is dead and has been since Sayu was in grade school. Because Soichiro was a police officer, he rarely ever comes home, which more or less made Light Sayu's father figure in her life. This only adds to the tear jerking moment when she realizes what he's become.
- Light's Palace. Jesus fucking christ is it just terrible. You remember how Light thought the world was rotting? Well, his Palace looks like a damned demilitarized zone. Buildings are dilapidated and ruined, the sky is gloomy and all you can see is just a world of decay. The only life this world has are the people Light thinks are his followers: people wearing nothing but white cloaks with candles, all mindlessly herded by angels as they head towards the tower where Shadow Light resides.
- Shadow Light/Kira's overall breakdown after the Phantom Thieves kick his ass. He's been reduced to pitifully begging for the Phantom Thieves to give him back his Treasure so he can continue existing. When they refuse, he asks how he's supposed to protect Sayu. That was his motivation the entire time he began this twisted crusade: he wanted to protect Sayu, and to do so, he became the greatest serial killer in modern history with a god complex.
- Joker's answer to that is something the readers already know, but it nonetheless hurts when the Wild Card explains to Kira his well-intentioned wish to protect his sister only managed to make her cry.
- Light's Treasure, as it turns out, is a family photograph of the Yagami Family. It features a young Light and an infant Sayu, who is being held by a still-living Sachiko Yagami.
- Justice, Rediscovered shows the aftermath of Light's change of heart. Like certain Mementos Targets, he doesn't turn himself in to the police, but the guilt is eating at him like mad. It gets to the point where he has nightmares and can't focus in class. One event even has him faint in the middle of school, and Sayu does her damndest to try to make sure he doesn't go do something stupid. She doesn't want to lose her brother, and she doesn't want her father to feel the pain of having to arrest and sentence his only son to death.
- Ryuk's Cruel Mercy. Light willingly relinquishes the Death Note...but Ryuk refuses because he wants to see how things play out. He even tells Light to keep the Death Note as a souvenir. Light obviously thinks Ryuk is clearly doing this For the Evulz.
- During dinner, Light happens to see the TV station's interview with Soichiro and Akechi, in which they discuss the Phantom Thieves and Kira, with both sides stating that the former are far more appreciated than a serial killer. Hearing his father puplicly denounce Kira, who happens to be Light, is enough to nearly bring the poor kid to tears. The worst part is that, at this point in time, Soichiro doesn't yet know that Light is Kira.
- Later chapters reveal that Soichiro has noticed Light's sudden depression, which coincides with the Kira killings stopping altogether. When L mentions the probability of Light being Kira, Soichiro realizes that it may be possible the Phantom Thieves stole Kira's heart if the murders have stopped...and Light's sudden bout of depression means that his son was the murderer he's been after all this time.
- Light awakening to his Persona shows the readers something that they probably never realized: Light's perfect look was because it was the only way he could achieve what he wanted in life. When he was regretting what he had done as Kira, we see that he never had any actual human interaction with his classmates. It gets further expanded upon after he obtains his Persona, in which Light reveals to Ryuk that because of how hard he worked and how the teachers favored him, everyone either only approached him because of his status as the number one honor student or they just flat out hated his guts.
- The story also reveals some backstory about the Niijima family: Soichiro and the Niijima sisters' father, named Masahiro in the story, were partners and were investigating Kaneshiro, who had just started to make a name for himself. When their investigation hit a dead end, Masahiro's informant got a lead and went to follow it up, but Soichiro stayed behind at home to look after Light with his wife after the former came down with a fever. The next day, Masahiro was found dead, having been killed in an ambush. Soichiro blamed himself for not being able to protect his partner.
- While we haven't seen any of the Niijimas interact with Soichiro, Makoto hints that Sae has a strained relationship, and we soon find out why: Soichiro hid the truth behind Masahiro's death to them in order to prevent them from going after the man in revenge sometime later in the future. Sae somehow found out, likely when she became a prosecutor. We haven't actually seen her reaction, but Soichiro received this from her at some point:"You had no right to hide this from us!"
- While we haven't seen any of the Niijimas interact with Soichiro, Makoto hints that Sae has a strained relationship, and we soon find out why: Soichiro hid the truth behind Masahiro's death to them in order to prevent them from going after the man in revenge sometime later in the future. Sae somehow found out, likely when she became a prosecutor. We haven't actually seen her reaction, but Soichiro received this from her at some point:
- Light is both worried and furious when Makoto confronts Kaneshiro, forcefully asking her what she was thinking.
