Character parents. Well I'm only playing one character right now...

And he has like, the best dad ever

Well did

Byakuya Ishigami was the biggest dork, and brought a lot of levity and probably a lot of forced fun to Senku's life - because he's been a serious, studious brat since he was in preschool.

It is not clear when he got Senku - as they are not biologically related.

Senku was the child of one of Byakuya's best friends, and somehow came into his custody for some reason Senku never bothered to ask because he sees his dad as his dad and that's it.

It's very much because of Byakuya that Senku loves space, and was likely inspired by Byakuya's own attempts to go to space.

It's just that Senku was not satisfied with one facet of science, each question led him from one to the next and he devoured knowledge like crazy.

They were very close, and worked together to get Byakuya accepted to JAXA, even though Senku was wrong and misguided in how he helped, but he was really young, but Byakuya was inspired by his efforts to push through and make up for his shortfalls.

Byakuya, when he realized his kid was this into science, sold his car to buy him pretty much everything he could ever need at six years old.

He was incredibly supportive of Senku's pursuits and dreams, and found him to be incredibly inspiring. He always believed Senku was going to grow up and do something amazing.

Aside from that, he really understood Senku. Certainly he teased him, often, but honestly he understood that he is not big on affection and honeyed words, and that this blunt, pragmatic outlook just had to be met where he was.

From when the petrification happened, until the day Byakuya died he endeavored to make the world a little more fun, less bleak if he could, and he held faith that Senku would revive someday.

He did a bunch of things to help him, and Senku is incredibly grateful.

As he's long gone, this does sadden Senku a lot, since while he believes a lot of people reunited with their family someday that just won't happen for him.

Also, the two of them are very alike in ideology, even in mannerisms as they spent a lot of time together and were definitely very close