RyuSae

RyuSae is the slash ship between Ryusei Shido and Sae Itoshi from the Blue Lock fandom.

Canon
Shido and Sae were temporary teammates on the Japan U-20 team for the Blue Lock Eleven vs. Japan U-20 arc. Shido showed deep interest in Sae many times, and the two frequently flirted with each other throughout the arc. Shido and Sae frequently flirt with one another, like making suggestive innuendos and comments, and using playful nicknames.

Japan U-20 Arc
The arc starts off with Ego Jinpachi naming the eleven starting players for the Blue Lock vs. U-20 match. Ego states that even though Shido is the second-best striker in all of Blue Lock, he had zero chemistry with the other players and that there is not a single player in Blue Lock that has the ability to understand/ handle Shido’s personality or playstyle. So instead of Shido playing for the Blue Lock Eleven as a starter, he was specially handpicked by Sae Itoshi to join the U-20 team.

Their first introduction to each other is when Sae tells Shido that Blue Lock is too small of a cage for him. He tells Shido to hand over his ego and go wild for Sae’s sake. Shido first reacts angrily but is much more intrigued by the end of the scene.

During the second half of the match, Shido is finally subbed in. He and Sae pair up instantly, overwhelming not only the other team but their own teammates as well. A fellow U-20 player Oliver Aiku even comments on how Shido and Sae are a match made in heaven.

After an incident with another player, Shido is rewarded with a free-kick opportunity to score. During this, he and Sae work together to plan the very best route Shido can take to score his goal. Sae encourages him to think outside of the box and imagine his very best goal rather than the “realistically possible” goal. Shido quickly comes up with his ideal goal and tells Sae that he says very exciting things. Sae tells him that this is the time to dream and to fall under his spell. Shido responds by asking if he’s Cinderella now, then say’s he’s falling in love. Together, Shido and Sae score the goal.

After their goal, Shido compliments Sae on his assistance. He tells Sae he likes him and asks for his number. Sae says he’ll give it over if Shido scores a hat trick (a hat trick is when a player scores three goals in a game). Shido now looks even more excited than he was before.

After a pass from Sae to Shido, Shido compares playing football with Sae to the feeling of electricity pulsing through his brain. Sae asks him to elaborate, and he answers by saying that he doesn’t really know, but this is the first time he’s ever felt that his freedom has been understood by someone. Shido blushes and comments on his excitement again. Sae reminds him that he still needs to score his goal before he gets too excited.

After Shido scores his second goal, his teammates run toward him to congratulate him, but he ignores them and runs straight for Sae to jump on his back. He declares that he wants to play football with him forever and that with Sae he feels a ‘special sensation’ he's never felt with anyone else before. Sae reminds Shido that he needs to score a hat trick before he’s rewarded, and even goes as far as calling Shido a horny demon. Shido responds to this by asking Sae if he can move in with him if he scores ten goals.

At the end of the U-20 match, Shido scored his required hat trick and reminds Sae of his promise to give Shido his number. Sae responds teasingly by asking if he can at least shower before he gives it over.

Manga Quotes
"I want your ego. Go wild for my sake."

- Sae to Shido, Chapter 109

"...Itoshi Sae chose not any of you here, nut Shido Ryusei instead."

- Ego to Blue Lock, Chapter 109

"Go wild, my little demon. You and I are going to be this game's headliners."

- Sae to Shido, Chapter 122

"Shido Ryusei, who even Blue Lock couldn't rein in... We'll finally find out the reason why he was picked... We'll be able to see 'The Egoist Desired by Itoshi Sae.'"

- Ego Jinpachi, Chapter 126

"Looks like those two... Are a match made in heaven."

- Oliver Aiku on Shido and Sae, Chapter 128

"While Blue Lock was unable to handle Shido, he managed to grasp Shido's vision and answered in kind with a flawless pass... I'm sure those two are are only just getting started-"

- Yoichi Isagi on Shido and Sae, Chapter 128

"Hey Itoshi Sae, that was a nice pass. Playing football with ya is pretty damn fun."

- Shido to Sae, Chapter 130

Fandom
FAN FICTION RyuSae tag on AO3