Hi I reblog a lot and draw sometimes

Byakuya is introduced in the tenth chapter of the manga as a dotting father who sells his car to present Senku with scientific instruments he will need for a more efficient research. This car is Byakuya's means of transportation, and given that he is crying and shaking in this scene, it could not have been easy for him to lose it. But his love for Senku is so big, that he wants to support his son's passion even if it means sacrificing a great convenience for him.

And Senku? Senku truly fell in love with science at this moment.

If there is anything that Senku is, he is Byakuya Ishigami's son through and through. They may seem like two very different people, as Byakuya is an openly affectionate guy while Senku is more closed off with showing his true emotions. But Senku takes more from Byakuya than not, and one of them is by showing his love and/or care for others through giving the gifts of science.

And it starts with Byakuya.

[Bodysuit Acquired!]

Byakuya had failed his first attempt at being an astronaut ten years back, but he doesn't give up and tries again. Senku then creates a bodysuit that manipulates muscle movement to help Byakuya pass his swimming test. And while the bodysuit doesn't quite help Byakuya to swim, the thought Senku had put into it had motivated Byakuya more than ever to pass the test. This is one of the fundamentals of gifting– sometimes, it really is the thought behind it that matters.

This motivation is what Byakuya credits during his interview with JAXA for passing the tests. He understands that Senku might not have given him any words of encouragement, but this bodysuit was all the words that were needed between them. Senku wants Byakuya to achieve his dreams just as badly. It's the way Senku shows his love for his father.

And it's the way Senku shows his love for others too.

[Glasses Acquired!]

One of the primitive aspects of the Ishigami village is that it considers bad eyesight as a type of "disease". Fuzzy disease, to be exact.

Suika wears a melon mask at all times to help clear her eyesight, which Senku later reveals is due to the pinhole effect. She, however, has never told Senku or the others about having the fuzzy disease. Senku himself notes how odd it is for her to wear a melon around, and confronts her about it once he decides to create glass. This is one of the most beautiful scenes in Dr. Stone, as Suika finds out that her disease was never a disease, and is finally able to see as clearly as the others. Senku basically gives her perfect eyesight, something she didn't even know was possible before.

[Antibiotics Acquired!]

One of the most beloved people in this village is the priestess, Ruri. Two of Senku's new friends, Kohaku and Chrome are deeply affected by her unknown fatal disease. Senku is such a person who would help a stranger even if there is no benefit to do so (though he would never admit to it), what more a person who his new friends truly love and care about. He cures Ruri of pneumonia, giving her a chance to live a life without the worry of it being her last day every day.

[Cola Acquired!]

Senku forms an alliance with Gen, who plays the role of Tsukasa's spy, for the promise of a bottle of cola. Both Senku and Gen are aware that the cola is only a front for Gen's loyalty to Senku and the Kingdom of Science, for Gen needs his superficial reputation as a comfort and cannot simply join them if there is no personal benefit for him to do so.

This cola is also the first gift post-petrification that Senku brands himself on, probably because it represents the first gift that is not out of necessity and leans toward a comfort/luxury that they both used to enjoy in the modern world.

For a modern man such as Gen, drinking his favourite soda in the stone world might have been one of the happiest days in his life.

[Cotton Candy Acquired!]

Senku cares about people so much, even if the people in question have tried to kill him. Senku sees Homura as a soldier who is merely following the orders given by her leader, but he also sees the Homura as a lonesome girl sitting by herself on trees day and night.

As usual, Senku hides his kindness and care by showing an evil ulterior motive, such as turning Homura to their side using the cotton candy, but Ruri points out that this is a facade. Similarly to Gen, a person with such an ego is unable to seem as if he is doing something good out of the kindness of his heart.

[Stove Acquired!]

As winter approaches, the elders in the village are worried about losing people to the cold. Senku hears about this and creates a stove which has a multi-purpose of cooking and also radiating heat for the people to stave off the coldness of winter. And speaking of winter...

[Christmas Acquired!]

Senku hangs up lights in the tree for the "light bulb test" on a random night. Except the date isn't random at all and he drops enough hints for Gen to catch on that it is the night of Christmas. The significance of the day is only appreciated by Gen and himself, as they are the only modern timers in the village. It is for the sake of nostalgia, but Senku would rather be caught dead than admit that he is a sentimental guy with such irrational feelings.

And well, it all comes back to that scene with Byakuya, doesn't it? If you recall, Byakuya calls himself "Santa" while giving the scientific presents to the young Senku. This indicates Senku received them during Christmas. Which means... Christmas is a sentimental day to Senku and his father. An anniversary of Senku receiving his Christmas presents from Byakuya, which led to his deeper dive into his science obsession. The beginning of it all, one would say.

And even though he's dead and buried, Byakuya never stops giving. He gives Senku the Ishigami village to provide Senku with allies. He gives Senku Lillian's music, because he believes in the light of music and understands the importance of media to society. He collects platinum till his last breath, because he believes that Senku will need it someday. Byakuya keeps on giving to Senku, because his love for his son is so huge and unconditional. And because he promised.