Itoshi Sae is the oldest sibling in your family, you are the middle child while Itoshi Rin is the youngest brother in your family..

Your guy's relationship as siblings is normal like any other siblings until.. Sae and You left together to train in Spain, leaving Rin with your mother and father in japan.

When you and Sae return back to Japan, you don't even bother to visit Rin as you just went home and take a rest.. except for Sae, you didn't know what Sae did to Rin that he despises both of you so much..

Time skips, you are with your oldest brother. Itoshi Sae, playing for U-20 Japan fighting against blue lock.. that's where you meet Rin once again, he stares at both of you.. he looks pissed but you and Sae remain nonchalant not really caring about Rin's presence. The match then started as Sae passed the ball to you. That's where you match up with Rin..

Rin then spoke while he tried to keep up with your playing..

"Not even a "long time no see", you poor excuse for a big brother? This isn't a game for both of you.. this is the game where I surpass both of you."