Unmarked spoilers below!
Finding out your cool dad has been dead for thousands of years can have that effect...
- Just from chapter 1 alone have make people terrified from being turned into stone and some of them even begging for help but to no avail considering the current situation was engulfing to entire humanity.
- On that note, since the beam affects only humans (and swallows), picture yourself as that puppy that was being walked by a girl who had been petrified. The poor little thing is so scared and desperate to see someone it holds dear becoming a statue, unmoving and unfeeling, and probably starved to death confused and alone.
- After being told of mankind's history of scientific progress, Chrome sheds tears over the fact that the vast knowledge and achievements humanity had obtained through millions of years of research all vanished in one day.
- On a related note, the shot of the International Space Station, a symbol of humanity united in the pursuit of science, falling apart and crashing to Earth.
- You can think of Ginro as a Cowardly Lion or a mere goof-ball all you want. But when he was full blown crying over the decision of cutting the bridge and subsequently sending his brother to his death or letting Tsukasa's army over the bridge into the village. It's difficult not to feel bad for him.
- It might only be a few panels, but Senku crying over Byakuya's grave is somewhat depressing.
- To add context: Not only is Senku crying over the grave of his father, who has been dead for thousands of years: is also the death of the coolest dad ever, the same man who sold almost everything to help a young Senku accomplish his dream. The fact this man had so much faith in his son to even left him a message to the distant future (Which could have been lost, but by chance of miracle it didn't) is just shockingly optimistic. Adoptive or not, Byakuya is the coolest dad ever.
- There's also the fact that up to this point, Senku had only really expressed overall enthusiasm, shock, frustration, and anger at everything. Even when talking about reviving humanity he sounds more determined than anything. Here, we see Mr. Awesome Ego in grief to the point of tears.
- The anime's second closing sequence opens with a young Senku holding his father's hand and going stargazing with him. At the end, he reaches out his hand for his father again... only to wake up with tears in his eyes in the Stone World. Then, he dries his eyes and goes stargazing alone. Senku may not be much for sentimentality, but he clearly misses his father.
- There's also a fridge-tearjerker element to this as well: Senku all this time has been optimistic about reviving people from the petrification. Given his reaction to finding out about his father, it's clear Senku had hoped that his father had been petrified as well even though he knew Byakuya was on the space station. The fact that Byakuya died of old age means that he's one of the only people that Senku can not bring back no matter how advanced or miraculous his science became. It's a double-whammy where one of Senku's loves (science, which has helped him get everything he had planned for until now) is unable to save another thing he loves (his father) and it just devastated him.
- Chapter 83: After all they've been through fighting each other, Senku and Tsukasa have an honest, ordinary conversation while Senku gets ready to kill Tsukasa in order to put him in cryogenic stasis.
- Chapter 115 finally reveals how Byakuya died: He spent the rest of his life, even after his fellow astronauts had all died, panning a river for rare metals so that he could store them in a "time capsule" and send them to Senku. Eventually his body gave out and he collapsed, gazing at the reflection of space in the water. Then he caught sight of the International Space Station, still visible in the night sky, and shed a Single Tear before passing on, thinking of his son.
- The reveal of how Soyuz managed to survive Ibara and escape. On the day the chief was petrified, Ibara also intended to kill Soyuz, an infant at the time, in case he inherited his father and mother's impressive memories and could remember him turning the chief to stone later in life. However, just as he was about to be done in, a woman jumped in and kept him from doing so. She's never named, and it's unknown if she was Soyuz's mother or just a villager loyal to the chief. But when Ibara declares the woman is kidnapping Soyuz, rather than risk the baby being taken from her, she battles her way out past several of the villages guards to get Soyuz to safety and sails away on a boat. However, as she sails away, we see she's teary eyed and has what looks to be a deep, bleeding gash in her side. And considering Soyuz was told he simply drifted on shore of Ishigami village as a baby, no mention of any woman on board with him, it seems she didn't make it. A massive act of bravery from her saved his life, and it's likely no one will ever even know her name or who she was.
- Chapter 148: When they finally make it to America, any faint spark of hope they had of humanity outside of Japan reviving too was quickly crushed when they see the numerous number of statues around. It only gets worse when they see groups of statues all clumped together due to the amount of cars people drive in America.
- Team Stanley's merciless assault on Team Science. Senku goes on to send Luna and Chelsea away, supposedly to be extra revivers in case something goes wrong, but the latter immediately recognizes that he's actually sending them away because they have no combat ability and they're all fully expecting the base to be wiped out. She can't even maintain the lie when she's out of reach, bawling like a baby.
- Taiju's seeming death is no slouch either. Poor kid gets blasted and charred, lying in critical condition, while Gen is pleading for him to get up.
Gen: Aren't you meant to be invincible? No matter what abuse you take... you always pop right back up. Isn't that right, dear Taiju? - In Chapter 194, after the heroes are forced to let Why-Man petrify the whole world to heal their injuries following revival, Suika is unpetrified years later. At first she is determine to revive all her friends. However, she finds out that Senku didn't have any revival fluid on him. She then realizes that she will run out of food and she'll starve to death on her own, which pushes her to tears. Thankfully, she remembers that Senku went through the same loneliness before reviving Taiju, and begins her own search for everyone's petrified bodies, believing one of them will have the revival fluid.
- Dr.Stone Reboot: Byakuya : Byakuya's Robot Buddy remained dedicated of constructing the ISS while being hopeful for Byakuya to return someday without it knowing he already passed away more than 3000 years ago since he first arrived on Earth.
