cracks knuckles "it's on"
So much fun his songs repeatedly emphasize him starting to look more at the moment and seeing the bright things in life, yes. He might fail at making tennis fun, but he's no Tezuka, there's enough fun outside of tennis and he aims to enjoy life because it's precious.
Songs aren't official. If they were, Icchan is now a divorcee and Shinji has killed himself already.
Tezuka not having fun is also something I call bs on. It's not because he doesn't show it that he isn't having fun, and mountaineering and fishing are both valid hobbies that don't require to have you laughing to death to enjoy.
It seems defaulting is Saeki's... default strategy

:
The material itself keeps telling us he's handsome and refreshing, though. Brightening days with presence is still looks.
I'm taking the fanbooks out for this, because sometimes the facts have to be laid out on table.
Time's he's called handsome:
"Uselessly handsome" / Yakiniku episode
/Pairpuri episode
"Also, okara is said to make one’s skin beautiful. Could the reason for Saeki’s beautiful skin also be explained by this!? " /20.5
What an overwhelming amount of "handsome". Now, the fanbook don't seem to mention anything about his personality though? Nothing substantial? I mean, Saeki is only about good looks ya know. Hm, lemme flip through 20.5 and 40.5...
"Normally a gentle-spirited, good young man, once he stands upon the court, the side of him that has the ruthlessness of a gambler becomes apparent! "
"He’s kind and he’s smart, so he’s a trustworthy comrade~. But that said, I never want to get on his bad side and wind up as his enemy."
"He seems to be a prodigy. However, Saeki’s true worth lies in the persistence of his soul…! When the pride that lurks inside of him is provoked, his fighting spirit causes him to bear his fangs, and his relentlessness will cause the acceleration to increase. "
"When he’s at a disadvantage, he won’t run away. That unfazed resolution is a worthy trait. "
"He has a flexible way of thinking, and he’s the type to have many hidden talents. Because he has an intellectual and gentle personality, he is liked by many people. Since he’s extremely popular, he has leader-like qualities and is good at directing people. That is to say, as he is involved with the student council, he aims to improve the school lives of the students from his position there, and as the figure who puts a great deal of effort into that, he is able to address a large group of students. However, he also has an egotistical and presumptuous side, and he’s prone to behaving unpredictably and being reckless. Because of this, there are also incidents in which this stubborn and overbearing aspect of him makes an appearance."
"You’re the guy who likes to do things fair and square. "
Wow. Saeki's emphasis is really on his good looks. I can't believe that there's nothing else. /flips hair
Win, to make a mark, to finish what they started, because tennis is his soul and he desperately fought to play tennis again. There's a lot of difference between on-court and off-court Yukimura, it just depends on the situation. If you're thinking about him with his team during practice, that's still on court. But you're forgetting the seaside festival and the time when he invited Shiraishi to the rooftop garden, his interactions with the plant trio during the U-17 camp, and much much more. And I'm not saying you need angst to make a character deep, it's just that there are many sides to Yukimura with many little things like him throwing plays for the school festival that add character. "He likes a certain style of painting and a general artistic movement of a more emotionated reality, showing his appreciation for the feelings of man" vs "he likes sandcastles

:"
Okay, that's fair. Yuki is more gentle off court. This rebuttal was against the fact that Saeki's facts aren't deep enough, simply labels. But if you want me to make up reasons as to why Saeki likes sandcastles, in the same vein as why Yukimura doesn't just think that Renoir paintings are nice but a feeling of man, let me elaborate.
Okay, so, Saeki grew up at the seaside, making sandcastles is probably a common activity. He might have done it a lot, and it's an important part of his childhood, in the same vein as Icchan's favorite hobbies are clam gathering. It doesn't speak to them on a deep level with the feelings of man, it's simply something they grew up with and liked enough to continue doing it in a more mature way. For teenagers.
Both are qualified hobbies with their own reasons. Neither is better than the other.
We aren't assuming that, I'm talking about hypothetical and rare incidents, because not everything is gonna go well, and everyone is human. Yukimura will be a listening and understanding ear, and after you've sorted through your thoughts, he'll honestly talk it over.
There's always gonna be times when people let feelings dominate their actions instead of reason, everywhere in life, and Yukimura won't let his responses be equally dominated. In real life, sometimes it's better to listen, keep calm and de-escalate.
Sae'd do the same. Nuff said. It's not something every boy does, but it isn't restricted to Yukimura alone, especially not among the buchous.
Sand is course, rough and it gets everywhere, and in the end, the waves of the sea wipe the castle away anyway. And if not the water, it'll be the sun evaporating the water holding the sand together. And if not the sun, some people are assholes who like to kick sandcastles.
Painting >>> sandcastles
Making sandcastles is a lot more about the process than about the final product. The way that Sae doesn't care if his hard work gets lost, shows that he doesn't get to hung up about things, he simply carries on and makes a new one, enjoying it all the same.